Shortcuts to toggle UI elements

[utopiaeh]

Currently, in Zed, shortcuts to open UI elements (e.g., Project Tree, Git Panel) are separate from the ones that close them. In IntelliJ IDEA, the same shortcut is used to toggle visibility (open/close).

Something similar to how the terminal works now. The main idea should be to keep both variants: one shortcut that closes the side panel as it does now, but it would also be nice to use the same shortcut to toggle it open and closed.