## The basics
- [x] I [validated my changes](https://developers.google.com/blockly/guides/contribute/core#making_and_verifying_a_change)
## The details
### Resolves
Fixes#9027
### Proposed Changes
Ensure that a block being dragged is properly focused mid-drag.
### Reason for Changes
Focus seems to be lost due to the block being moved to the drag layer, so re-focusing the block ensures that it remains both actively focused and selected while dragging.
The regression was likely caused when block selection was moved to be fully synced based on active focus.
### Test Coverage
This has been manually verified in Core's simple playground. At the time of the PR being opened, this couldn't be tested in the test environment for the experimental keyboard navigation plugin since there's a navigation connection issue there that needs to be resolved to test movement.
It would be helpful to add a new test case for the underlying problem (i.e. ensuring that the block holds focus mid-drag) as part of resolving #8915.
### Documentation
No new documentation should need to be added.
### Additional Information
This was found during the development of https://github.com/google/blockly-keyboard-experimentation/pull/511.
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