feat(starfish): rank commit-syncer and header-synchronizer peers by responsiveness

[polinikita]

Sub-issue of #12030.

Extend the per-peer responsiveness ranking introduced for the transactions synchronizer (#12112, implemented by #12038) to the remaining consensus synchronizers.

Scope

• Commit syncer (regular + fast): prefer responsive peers when fetching commits and their referenced blocks; scale recorded latency by delivery shortfall.
• Header synchronizer (live, periodic, and startup probe): prefer responsive peers when fetching block headers.
• Re-expand the shared PeerResponsiveness tracker to multiple fetch sources (per-source effective latency), including any startup bootstrap-probe seeding removed when the module was narrowed to the transactions synchronizer.
• Same guarantees as the tx-synchronizer work: preference within the already-eligible candidate set only; safety/liveness bounds and full response verification stay intact.

Dependencies

• Depends on feat(starfish): rank transaction-synchronizer peers by responsiveness #12112 — to be done in a follow-up PR after the transactions-synchronizer ranking is tuned.