Create a button + menu component, and use it to show the show/hide pane menu instead of the current approach (again)

[bkrmendy]

Problem
The current approach (button with checkboxes in the secondary menu) is aw(kward/ful) because it stays open and creates a separate mode that we then need to exit out of.

Solution

1. Create a button-opens-a-menu component, make sure the menu opens in relative to the button not the mouse (it's not a context menu). Note the button highlight when the menu is open.
2. Use it instead of the secondary toolbar for the show/hide navigator/inspector/codeeditor menu
3. For the context menu, use the [checkbox][label][keyboard shortcut] three-column format
4. Populate it with the current settings and keyboard shortcuts

For clarity, this is the standard pattern that gets used in lots of UIs all over the place, including VSCode itself and Figma