update-eventing-function for Eventing CLI

In the UI, We can pause-edit-resume a function.
On the CLI, We could pause-import-resume a function.

However, "import" seems to overwrite a function and lose its place in the source bucket. This would forces to "resume-from-now" and miss some data or go back to the vert beginning.
There doesn't seem to be an "update-eventing-function" on the cli which matches the "edit Javascript" on the UI.

another issue we are having is not knowing then the eventing function has completed its action. Since the commands seem to be asynchronous, we cannot script the commands

undeploy func1

delete func1

import func1

The import fails, since we don't know when the function is deleted. We need something like a --wait flag, which would make the execution synchronous.