Allow quick pick to show a tooltip

[TylerLeonhardt]

One follow up from #173716 ...

• Invalid Python environment in the kernel selection list. This usually happens when users have a partially broken Python environment. Jupyter or Python extension might be able to fix it, so we still present it to users (we don't automatically fix it for users, as it requires user consent). Currently, we put a warning codicon in the quick pick item title, but users don't know what the reason behind the "warning" is.

For this case, we can enable the ability to describe the issue with the ⚠️ by allowing a quick pick item to be hovered (or "hovered" via Ctrl+Space)

[TylerLeonhardt]

Addressed in #174417