feat: additional logging for new_block handler

[cylewitruk]

Description

Adds a little additional logging to the new_block event observer handler to help with healthchecks of partner signers. This will now record the block hash, height, parent and bitcoin anchor for log events within the handler.

Changes

• Additional logging and tracing spans
• Minor refactors to help optimize how/when the log lines are written and so they include the relevant fields

Testing Information

Checklist:

• I have performed a self-review of my code
• My changes generate no new warnings
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

[djordon]

Looks good. Had some nits and suggestions.