agent_ui: Add "Paste as Plain Text" to message editor context menu (#50625)
Eric Holk
created
Add the existing `PasteRaw` action to the right-click context menu in
the message editor, making it more discoverable. Previously it was only
available via the keyboard shortcut (Cmd+Shift+V / Ctrl+Shift+V) or
the command palette.
Release Notes:
- Added "Paste as Plain Text" to the agent panel message editor
right-click menu