Proposal: Extension points for Block Action Bar actions

[rbottema]

What we want to implement
Introduce extension points in the new backoffice so packages can add or adjust actions in the existing Block Action Bar (Block List / Block Grid), without replacing the block view.

Why this is needed
Current customization is mainly via blockEditorCustomView, which is great for rendering changes but heavy for simple action-level behavior and harder to combine with other extensions.

What you could do with it

• Add context-aware custom actions per block type
• Enable/disable or show/hide actions based on block state
• Trigger package-specific workflows directly from a block
• Keep the default block UI while still allowing focused extensions

Expected outcome
A lightweight, composable way to extend block interactions, with better compatibility between packages and fewer custom view workarounds.

[nielslyngsoe]

This is a good one, and we wanted to do this as well. I've also had several conversations with people previously where this was the solution for the problem.

So the question is just about priorities. Is this something you would like to provide a PR for?