Return focus to point of action when the off-canvas dialog closes

Problem/Motivation

When various actions happen in the layout builder focus is not returned to logical elements.

This means if you are using keyboard navigation and do an action you have to tab from top of the page each time.

Proposed resolution

Proposed focus elements

1. Add new section -> First "Add block" link in the section
2. Add new block -> Contextual links trigger for newly added block
3. Configure block -> Contextual links trigger for the updated block
4. Move block -> Contextual links trigger for the updated block (if added in #2995689: Allow reordering blocks without a pointer device → )
5. Configure section -> same configure section link

Remaining tasks

1. Figure out logic focus elements
2. Create patch
3. Test

User interface changes

API changes

None

Data model changes

None

Release notes snippet

None