After feedback from Russ, I realized that there are some extraneous assumeutxo methods
that are not necessary and probably just overly confusing. These include
- Validated*()
- IsBackgroundIBD()
and they can be removed.
Also add comment for g_best_block
This is a backport of core#21526 [2 & 3/12]
https://github.com/bitcoin/bitcoin/pull/21526/commits/ac4051d891e2d5c8ac130da16b85b9d880b44720
https://github.com/bitcoin/bitcoin/pull/21526/commits/665072a36df2e4c88705fedd4ac7c955d7f6a488
Backported out of order (unrelated refactorings first)