refactor: configure messaging when creating services (#1007)

Closes #1002

### Summary of Changes

* It's now possible to configure messaging (logging/user messaging) for
when creating services.
* The runner now uses the `MessagingProvider` instead of handling
messaging on its own.

packages/safe-ds-lang/src/language/lsp/safe-ds-messaging-provider.ts

@@ -9,6 +9,8 @@ import { Disposable } from 'vscode-languageserver-protocol';
  */
 export class SafeDsMessagingProvider {
     private readonly connection: Connection | undefined;
+    private logger: Logger | undefined = undefined;
+    private userMessageProvider: UserMessageProvider | undefined = undefined;
 
     constructor(services: SafeDsServices) {
         this.connection = services.shared.lsp.Connection;
@@ -18,8 +20,10 @@ export class SafeDsMessagingProvider {
      * Log the given data to the trace log.
      */
     trace(tag: string, message: string, verbose?: string): void {
-        if (this.connection) {
-            const text = this.formatLogMessage(tag, message);
+        const text = this.formatLogMessage(tag, message);
+        if (this.logger?.trace) {
+            this.logger.trace(text, verbose);
+        } else if (this.connection) {
             this.connection.tracer.log(text, verbose);
         }
     }
@@ -28,8 +32,10 @@ export class SafeDsMessagingProvider {
      * Log a debug message.
      */
     debug(tag: string, message: string): void {
-        if (this.connection) {
-            const text = this.formatLogMessage(tag, message);
+        const text = this.formatLogMessage(tag, message);
+        if (this.logger?.debug) {
+            this.logger.debug(text);
+        } else if (this.connection) {
             this.connection.console.debug(text);
         }
     }
@@ -38,8 +44,10 @@ export class SafeDsMessagingProvider {
      * Log an information message.
      */
     info(tag: string, message: string): void {
-        if (this.connection) {
-            const text = this.formatLogMessage(tag, message);
+        const text = this.formatLogMessage(tag, message);
+        if (this.logger?.info) {
+            this.logger.info(text);
+        } else if (this.connection) {
             this.connection.console.info(text);
         }
     }
@@ -48,8 +56,10 @@ export class SafeDsMessagingProvider {
      * Log a warning message.
      */
     warn(tag: string, message: string): void {
-        if (this.connection) {
-            const text = this.formatLogMessage(tag, message);
+        const text = this.formatLogMessage(tag, message);
+        if (this.logger?.warn) {
+            this.logger.warn(text);
+        } else if (this.connection) {
             this.connection.console.warn(text);
         }
     }
@@ -58,8 +68,10 @@ export class SafeDsMessagingProvider {
      * Log an error message.
      */
     error(tag: string, message: string): void {
-        if (this.connection) {
-            const text = this.formatLogMessage(tag, message);
+        const text = this.formatLogMessage(tag, message);
+        if (this.logger?.error) {
+            this.logger.error(text);
+        } else if (this.connection) {
             this.connection.console.error(text);
         }
     }
@@ -75,7 +87,9 @@ export class SafeDsMessagingProvider {
      * notification center.
      */
     showInformationMessage(message: string): void {
-        if (this.connection) {
+        if (this.userMessageProvider?.showInformationMessage) {
+            this.userMessageProvider.showInformationMessage(message);
+        } else if (this.connection) {
             this.connection.window.showInformationMessage(message);
         }
     }
@@ -87,7 +101,9 @@ export class SafeDsMessagingProvider {
      * notification center.
      */
     showWarningMessage(message: string): void {
-        if (this.connection) {
+        if (this.userMessageProvider?.showWarningMessage) {
+            this.userMessageProvider.showWarningMessage(message);
+        } else if (this.connection) {
             this.connection.window.showWarningMessage(message);
         }
     }
@@ -99,7 +115,9 @@ export class SafeDsMessagingProvider {
      * notification center.
      */
     showErrorMessage(message: string): void {
-        if (this.connection) {
+        if (this.userMessageProvider?.showErrorMessage) {
+            this.userMessageProvider.showErrorMessage(message);
+        } else if (this.connection) {
             this.connection.window.showErrorMessage(message);
         }
     }
@@ -131,6 +149,70 @@ export class SafeDsMessagingProvider {
             await this.connection.sendNotification(method, params);
         }
     }
+
+    /**
+     * Set the logger to use for logging messages.
+     */
+    setLogger(logger: Logger) {
+        this.logger = logger;
+    }
+
+    /**
+     * Set the user message provider to use for showing messages to the user.
+     */
+    setUserMessageProvider(userMessageProvider: UserMessageProvider) {
+        this.userMessageProvider = userMessageProvider;
+    }
 }
 
 /* c8 ignore stop */
+
+/**
+ * A logging provider.
+ */
+export interface Logger {
+    /**
+     * Log the given data to the trace log.
+     */
+    trace?: (message: string, verbose?: string) => void;
+
+    /**
+     * Log a debug message.
+     */
+    debug?: (message: string) => void;
+
+    /**
+     * Log an information message.
+     */
+    info?: (message: string) => void;
+
+    /**
+     * Log a warning message.
+     */
+    warn?: (message: string) => void;
+
+    /**
+     * Log an error message.
+     */
+    error?: (message: string) => void;
+}
+
+/**
+ * A service for showing messages to the user.
+ */
+export interface UserMessageProvider {
+    /**
+     * Prominently show an information message. The message should be short and human-readable.
+     */
+    showInformationMessage?: (message: string) => void;
+
+    /**
+     * Prominently show a warning message. The message should be short and human-readable.
+     */
+    showWarningMessage?: (message: string) => void;
+
+    /**
+     * Prominently show an error message. The message should be short and human-readable.
+     */
+    showErrorMessage?: (message: string) => void;
+}