Track headers presync progress and log it

Summary:
This is a partial backport of core#25717
https://github.com/bitcoin/bitcoin/pull/25717/commits/355547334f7d08640ee1fa291227356d61145d1a

Depends on D15167

Test Plan:
ninja all check-all

Run a header sync on mainnet and testnet, monitor the debug log

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Subscribers: Fabien

Differential Revision: https://reviews.bitcoinabc.org/D15168