Dal+Etherlink/Tests: run a DAL node

What

Launch a DAL node in Etherlink Tezt tests. This DAL node is used by the client to attest the DAL in the bake for command and by the rollup node to inject on the DAL.

Stacked on !13846 (merged).

Why

This is needed to run end-to-end tests of the DAL integration in Etherlink.

How

Manually testing the MR

I tested this with

dune exec etherlink/tezt/tests/main.exe -- alpha sequencer /proxy /dsn_node latest /flaky /slow -j 10

This currently runs 210 tests.

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