Rename network-related settings in config

[crusaderky]

Follow-up to #6933

This is very ugly and confusing:

https://github.com/dask/distributed/blob/34b18a92d5c6ca9020fb16d7dd3e0e493027c2e7/distributed/worker.py#L523-L528

We should rename

• distributed.worker.connections.outgoing to distributed.worker.transfer.incoming_count_limit
• distributed.worker.connections.incoming to distributed.worker.transfer.outgoing_count_limit

The renames must be added to distributed.config.aliases.

CC @hendrikmakait

[crusaderky]

The aliases are non-trivial because they are not yet supported in dask/dask: https://github.com/dask/dask/blob/222ea067db35f65787ee2a877b6e29bb85ae9eed/dask/config.py#L557-L558