Fix workflow improvements

Description of fix

UI

• Tools in Preview's left bar are always visible but disabled when review isn't available.
• toggle_annotations_keyframes moved to Annotate tool context.
• 'Unsupported media type for review' message added.
• Status change disabled for unsupported media type.

Shortcuts

• Ctrl/Cmd + Enter to confirm a text comment.

How to test it

Checklist

Please check if your MR fulfills the following requirements:

• Build was run locally and any changes were pushed
• Lint has passed locally without error
• CHANGELOG.md has been updated
• Branch has been rebased on merge branch

FYI: @dddjef @alefeve