Consider renaming events in wait from "reason" to "event"

[yorugac]

Right now waiting for Kubernetes events is defined like this:

let err = env.wait({
    kind: "Pod",
    name: "nginx",
    namespace: "default",
    reason: "Started",
});

While "reason" is the name used by Kubernetes for this field, it might also be confusing if one does not remember the exact structure of those events. So it makes sense to rename that field to just "event".

Sample Kubernetes events stream for reference:

NAMESPACE            LAST SEEN   TYPE      REASON              OBJECT                                                           MESSAGE
local-path-storage   27m         Normal    Created             pod/helper-pod-create-pvc-39172e80-a287-4f6c-abdc-fc6ad778d936   Created container helper-pod
local-path-storage   27m         Normal    Started             pod/helper-pod-create-pvc-39172e80-a287-4f6c-abdc-fc6ad778d936   Started container helper-pod

Related issue: #2