Restore the 'Select a Kernel' command on the interactive window.

[DavidKutu]

For #4479

For notebooks, there's the command 'Select Notebook Kernel', and for Interactive window there's 'Select a Kernel'

• Pull request represents a single change (i.e. not fixing disparate/unrelated things in a single PR).
• Title summarizes what is changing.
• Has a news entry file (remember to thank yourself!).
• Appropriate comments and documentation strings in the code.
• Has sufficient logging.
• Has telemetry for enhancements.
• Unit tests & system/integration tests are added/updated.
• Test plan is updated as appropriate.
• package-lock.json has been regenerated by running npm install (if dependencies have changed).

[rchiodo]

Does this still work with the old webview?

[DonJayamanne]

Please use UseVSCodeNotebookEditorApi intead of checking manually.
The logic keeps changing, hence its best to use the value UseVSCodeNotebookEditorApi.

[DonJayamanne]

Please use UseVSCodeNotebookEditorApi