TODO:
- [x] Double-check if we like the naming of the new actions
- [x] Only show keybinding hint once per option (e.g. if there are two
`allow_once` buttons only show it on the first one)
- [x] If there are multiple tool calls that need authorisation, only
show keybindings on the first tool call
- [x] Figure out which keybindings to use
- [x] Add linux keybindings
- [x] Add windows keybindings
- [x] Bug: long keybindings can make the buttons overflow


Release Notes:

- Add keybindings for authorizing tool calls (`agent: Allow once`,
`agent: Allow always`, `agent: Reject once`) in the agent panel

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Co-authored-by: Agus Zubiaga <agus@zed.dev>