feat: add constant fee to setting block producer metadata

[LGLO]

Description

Adds additional, constant, configurable burn hold to Block Producer Metadata update operation to make attacks on the unbounded storage infeasible.

REF: ETCM-11960

Checklist

• Commit sequence broadly makes sense and commits have useful messages.
• The size limit of 400 LOC isn't needlessly exceeded
• The PR refers to a JIRA ticket (if one exists)
• New tests are added if needed and existing tests are updated.
• New code is documented and existing documentation is updated.
• Relevant logging and metrics added
• Any changes are noted in the changelog.md for affected crate
• Self-reviewed the diff