Add selection vector repartitioning

### Is your feature request related to a problem or challenge?

Add a mode that outputs selection vectors (for now let's use dense boolean arrays so it can be added to RecordBatch) in RepartitionExec. The array outputs true for each row that has hash % total_partition == current_partition (and false if not).

### Describe the solution you'd like

_No response_

### Describe alternatives you've considered

_No response_

### Additional context

_No response_

Start by locating RepartitionExec and reading how it currently computes partition assignments and produces RecordBatch output. Trace the existing hash and partitioning path, then identify the relevant tests or add coverage for dense boolean selection vectors; done means each row is true only for its assigned partition and the vectors are available in the output batch.

Written by the indexing model from the issue text.