Add experiment to change interpreter status bar item into a language status item

[karrtikr]

• Use language status API to move interpreter info inside the "Python" item in the right side.
• It is unpinned by default.

After pinning and hovering:

When interpreter selected is invalid:

After pinned:

[karrtikr]

@luabud The getting started experience are currently misleading with the experiments. For eg. Python now only appears if a Python file is opened, so user won't see anything in the status bar in the below screenshot.

Should we have different steps based on what experiment the user is? Also, doesn't look like we can teach a user how to select an interpreter without them opening a python file first.

Same question regarding #18282