Clarify field names for simplex p2p messages

[samliok]

Why this should be merged

Small nit that was not found in the last merged simplex pr. Quorum certificates can be notarizations or finalizations so the old field name doesn't make sense. Similarly, changed names for other fields to block_header & metadata for more clarity.

How this works

How this was tested

Need to be documented in RELEASES.md?

no

[Copilot]

Pull Request Overview

Renames the finalization field in the QuorumCertificate message to block_header for better clarity in both the .proto definition and generated Go code.

• Changed the QuorumCertificate field name in p2p.proto
• Regenerated p2p.pb.go to update struct field and accessor method

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
proto/p2p/p2p.proto	Renamed finalization → block_header in the message definition
proto/pb/p2p/p2p.pb.go	Updated generated struct field and GetFinalization → GetBlockHeader

Comments suppressed due to low confidence (2)

proto/p2p/p2p.proto:486

• Renaming this field is a backward-incompatible change for existing protobuf consumers; consider providing a deprecated alias for finalization or documenting a clear migration path in your release notes.

BlockHeader block_header = 1;

proto/p2p/p2p.proto:486

• [nitpick] Add a comment above this field in the .proto file to describe what block_header represents, improving readability and future maintenance.

BlockHeader block_header = 1;