Dac: Refactor dac plugin into bin dac node

Context

Moves RPC server and all of DAC logic out of the protocol plugin into lib_dac_node. The protocol plugin only exposes behaviours related to Sc_rollup_reveal_hash.

Note to reviewers: May be easier to review per commit

Closes: #4688 (closed) Closes: #4689 (closed)

Manually testing the MR

None. Unit tests in proto_alpha/lib_dac were migrated to lib_dac_node/ and are all green. Tezt tests for dac.ml are green.

Checklist

• Document the interface of any function added or modified (see the coding guidelines)
• Document any change to the user interface, including configuration parameters (see node configuration)
• Provide automatic testing (see the testing guide).
• For new features and bug fixes, add an item in the appropriate changelog (docs/protocols/alpha.rst for the protocol and the environment, CHANGES.rst at the root of the repository for everything else).
• Select suitable reviewers using the Reviewers field below.
• Select as Assignee the next person who should take action on that MR