This MR crafts an attestation without DAL when there is no companion key and issues a warning about it.

This MR also issues a warning if the companion key is missing from the wallet.

Manually testing the MR

This will be in a follow-up MR.

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