show api documentation on mouse click

[devoncarew]

• show api documentation on mouse click

On a mouse click, request api docs from the server and render into a panel at the bottom of the editor. On a mouse click in whitespace, hide the doc panel.

We may consider moving this panel - and the console output panel - to using a split view in the future, to allow for user re-sizing.

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[parlough]

Looks great to me, thanks!

The one thing that stood out to me that would be nice to improve later, either with user resizing or otherwise, was the panel being the same size even if there was only a title and no doc comment, such as for a local variable with just its type.