282019cd3ddb060db350654e6f855f7ea37e0d34 refactor: add kernel/cs_main.* (fanquake)
Pull request description:
One place to find / include `cs_main`.
No more:
> // Actually declared in validation.cpp; can't include because of circular dependency.
> extern RecursiveMutex cs_main;
Ultimately, no more need to include `validation.h` (which also includes (heavy/boost filled) `txmempool.h`) everywhere for `cs_main`. See #26087 for another example of why that is useful.
ACKs for top commit:
ajtowns:
ACK 282019cd3ddb060db350654e6f855f7ea37e0d34
Tree-SHA512: 142835b794873e7a09c3246d6101843ae81ec0c6295e6873130c98a2abfa5f7282748d0f1a37237a779cc71c3bc0a75d03b20313ef5398c83d4814215cbc8287