Add menu item to toggle code lenses

[rchl]

Code Lens is one of those features that is IMO too annoying to have always enabled but can be useful to use once in a while to catch un-referenced symbols and such so I think it deserves its own toggle like that.

Threw it in very quickly based on Inlay Hints and Hover Popups toggles. Might have missed something.

[predrag-codetribe]

based on the PR title,
I would say that you explicitly just added the command in the menu.

Currently for inlay hints there is a command in the command palette,
do you think that it should be added there, for consistency?

Also by looking at the name "LSP: Show Code Lens"
it is not obvous that this command can be toggled? "LSP: Toggle Code Lens" makes more sense to me

But I get why "LSP: Toggle Code Lens" was choosen, because inlay hints toggle also uses "LSP: Show Inlay Hint"

[rchl]

Also by looking at the name "LSP: Show Code Lens"
it is not obvous that this command can be toggled? "LSP: Toggle Code Lens" makes more sense to me

consistency

As far as whether it's obvious or not that it can be toggled... this is about naming conventions for checkboxes. If it's clear that it's a checkbox then it would be even enough to just say "LSP: Code Lenses" since it would be clear from the context that it's a toggle. On Mac it's not that obvious though when checkbox is disabled so maybe that's why "Show..." is better.

And of course we should try to be consistent with ST but it seems like ST uses checkboxes very sparingly. It prefers to instead change the item title based on the state (showing "Show..." or "Hide...").