Improve hotkey ux on unified canvas

[codedealer]

What type of PR is this? (check all applicable)

• Refactor
• Feature
• Bug Fix
• Optimization
• Documentation Update
• Community Node Submission

Have you discussed this change with the InvokeAI team?

• Yes
• No, because:

Have you updated all relevant documentation?

• Yes
• No

Description

This PR fixes problems with hotkey interaction on Unified Canvas tab, mostly in regards to staging area toolbar.

• Gallery items no longer switch when navigating through staging images
• Quick move tool (when holding space) is properly interactive without having to manually focus on canvas stage
• The current staging image can be reliably accepted by pressing enter
• Additionally, pressing ESC while staging discards all images and shift+s saves the current one into gallery

Related Tickets & Documents

• Closes [bug]: Left/Right arrow losing context #5521

QA Instructions, Screenshots, Recordings

1. Go to Unified Canvas
2. Select brush tool
3. Generate images
4. While in staging mode: navigating with [left] and [right] keys should circle through staging images while the gallery's cursor position should stay the same.
5. Pressing [shift+s] should save the current staged image to the gallery given it's not hidden ("show results" is "on")
6. Pressing [enter] should accept the current staged image
7. Alternatively, Pressing [esc] should discard all images
8. Right after accepting/discarding staging images (when focus is on window) holding [space] should correctly switch to move tool

Merge Plan

This PR can be merged when approved

Added/updated tests?

No frontend tests

[psychedelicious]

Thanks!

One issue with the change to the space hotkey.

[psychedelicious]

Thanks for taking care of these issues and improving the UX!