DAL/Tests: Check that when attestation_lag changes, publication cannot be attested in the protocol next to the one of their publication

What

Add a test to check that publication which should not be attested due to stitching are not attested.

Why

Because when attestation_lag changes, it is required to not attest some publications.

How

By publishing at every level around a migration and checking that only the publications expected to be attested really are.

Manually testing the MR

It adds the test: make && dune exec tezt/tests/main.exe -- --file tezt/tests/dal.ml migration dal attestation_lag alpha --log-file /tmp/exp_$(date "+%Hh%M").log