Add key bindings for EditModel navigation

[google-labs-jules]

Added requested key bindings to the Edit view and its components.

• EditModel now supports ctrl+k and ctrl+j for cycling through fields, mirroring shift+tab and tab.
• ChoiceComponent and MultiButtonComponent now support h and l for horizontal navigation, mirroring left and right.

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PR created automatically by Jules for task 15231469186273570586 started by @shazow

[google-labs-jules]

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