bug: jest types from tsconfig.json could require extra jest dep

[gpbl]

• In some cases, the jest types in our tsconfig.json require users to install jest. See this discussion: Typescript Error: Cannot find type definition file for @testing-library/jest-dom . #2628).
• They have probably been added there for running tests and keep the type checking working in vscode.
• We should move the Jest types to a tsconfig.tests.json and configure vscode AND jest to use this config instead.

Not sure yet if the reported issue is reproducible. Yet, it would be nice to remove the jest types from the main /tsconfig.json, while keeping the tests and Jest extension working in VS Code (e.g. by specifying to use tsconfig.tests.json instead).