[refactor] Add versionbits deployments to deploymentstatus.h

Adds support for versionbits deployments to DeploymentEnabled,
DeploymentActiveAfter and DeploymentActiveAt. Also moves versionbitscache
from validation to deploymentstatus.

src/validation.h

@@ -24,7 +24,6 @@
 #include <sync.h>
 #include <txmempool.h> // For CTxMemPool::cs
 #include <txdb.h>
-#include <versionbits.h>
 #include <serialize.h>
 #include <util/check.h>
 #include <util/hasher.h>
@@ -1020,8 +1019,6 @@ public:
 /** Global variable that points to the active block tree (protected by cs_main) */
 extern std::unique_ptr<CBlockTreeDB> pblocktree;
 
-extern VersionBitsCache versionbitscache;
-
 /**
  * Determine what nVersion a new block should use.
  */