Merge bitcoin/bitcoin#29039: versionbits refactoring

e3014017ba test: add IsActiveAfter tests for versionbits (Anthony Towns)
60950f77c3 versionbits: docstrings for BIP9Info (Anthony Towns)
7565563bc7 tests: refactor versionbits fuzz test (Anthony Towns)
2e4e9b9608 tests: refactor versionbits unit test (Anthony Towns)
525c00f91b versionbits: Expose VersionBitsConditionChecker via impl header (Anthony Towns)
e74a7049b4 versionbits: Expose StateName function (Anthony Towns)
d00d1ed52c versionbits: Split out internal details into impl header (Anthony Towns)
37b9b67a39 versionbits: Simplify VersionBitsCache API (Anthony Towns)
1198e7d2fd versionbits: Move BIP9 status logic for getblocktemplate to versionbits (Anthony Towns)
b1e967c3ec versionbits: Move getdeploymentinfo logic to versionbits (Anthony Towns)
3bd32c2055 versionbits: Move WarningBits logic from validation to versionbits (Anthony Towns)
5da119e5d0 versionbits: Change BIP9Stats to uint32_t types (Anthony Towns)
a679040ec1 consensus/params: Move version bits period/threshold to bip9 param (Anthony Towns)
e9d617095d versionbits: Remove params from AbstractThresholdConditionChecker (Anthony Towns)
9bc41f1b48 versionbits: Use std::array instead of C-style arrays (Anthony Towns)

Pull request description:

  Increases the encapsulation/modularity of the versionbits code, moving more of the logic into the versionbits module rather than having it scattered across validation and rpc code. Updates unit/fuzz tests to test the actual code used rather than just a close approximation of it.

ACKs for top commit:
  achow101:
    ACK e3014017ba
  TheCharlatan:
    Re-ACK e3014017ba
  darosior:
    ACK e3014017ba

Tree-SHA512: 2978db5038354b56fa1dd6aafd511099e9c16504d6a88daeac2ff2702c87bcf3e55a32e2f0a7697e3de76963b68b9d5ede7976ee007e45862fa306911194496d

test/lint/lint-circular-dependencies.py

@@ -21,6 +21,7 @@ EXPECTED_CIRCULAR_DEPENDENCIES = (
     "qt/transactiontablemodel -> qt/walletmodel -> qt/transactiontablemodel",
     "wallet/wallet -> wallet/walletdb -> wallet/wallet",
     "kernel/coinstats -> validation -> kernel/coinstats",
+    "versionbits -> versionbits_impl -> versionbits",
 
     # Temporary, removed in followup https://github.com/bitcoin/bitcoin/pull/24230
     "index/base -> node/context -> net_processing -> index/blockfilterindex -> index/base",