Closes #45783 

`Menu` key or `Shift + F10` shortcut wasn't supported in project panel
for opening the context menu, this PR fixes it.

Release Notes:
- Added an action and default keyboard shortcuts to open the context
menu in the project panel. You can now bind
`project_panel::OpenContextMenu` to deploy the context menu at the
currently selected entry in the panel.

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Co-authored-by: MrSubidubi <finn@zed.dev>