Merge bitcoin/bitcoin#23173: Add ChainstateManager::ProcessTransaction

0fdb619aaf [validation] Always call mempool.check() after processing a new transaction (John Newbery)
2c64270bbe [refactor] Don't call AcceptToMemoryPool() from outside validation.cpp (John Newbery)
92a3aeecf6 [validation] Add CChainState::ProcessTransaction() (John Newbery)
36167faea9 [logging/documentation] Remove reference to AcceptToMemoryPool from error string (John Newbery)
4c24142b1e [validation] Remove comment about AcceptToMemoryPool() (John Newbery)
5759fd12b8 [test] Don't set bypass_limits to true in txvalidation_tests.cpp (John Newbery)
497c9e2964 [test] Don't set bypass_limits to true in txvalidationcache_tests.cpp (John Newbery)

Pull request description:

  Similarly to how #18698 added `ProcessNewBlock()` and `ProcessNewBlockHeaders()` methods to the `ChainstateManager` class, this PR adds a new `ProcessTransaction()` method. Code outside validation no longer calls `AcceptToMemoryPool()` directly, but calls through the higher-level `ProcessTransaction()` method. Advantages:

  - The interface is simplified. Calling code no longer needs to know about the active chainstate or mempool object, since `AcceptToMemoryPool()` can only ever be called for the active chainstate, and that chainstate knows which mempool it's using. We can also remove the `bypass_limits` argument, since that can only be used internally in validation.
  - responsibility for calling `CTxMemPool::check()` is removed from the callers, and run automatically by `ChainstateManager` every time `ProcessTransaction()` is called.

ACKs for top commit:
  lsilva01:
    tACK 0fdb619 on Ubuntu 20.04
  theStack:
    Code-review ACK 0fdb619aaf
  ryanofsky:
    Code review ACK 0fdb619aaf. Only changes since last review: splitting & joining commits, adding more explanations to commit messages, tweaking MEMPOOL_ERROR string, fixing up argument name comments.

Tree-SHA512: 0b395c2e3ef242f0d41d47174b1646b0a73aeece38f1fe29349837e6fb832f4bf8d57e1a1eaed82a97c635cfd59015a7e07f824e0d7c00b2bee4144e80608172

src/rpc/rawtransaction.cpp

@@ -946,12 +946,13 @@ static RPCHelpMan testmempoolaccept()
 
     NodeContext& node = EnsureAnyNodeContext(request.context);
     CTxMemPool& mempool = EnsureMemPool(node);
-    CChainState& chainstate = EnsureChainman(node).ActiveChainstate();
+    ChainstateManager& chainman = EnsureChainman(node);
+    CChainState& chainstate = chainman.ActiveChainstate();
     const PackageMempoolAcceptResult package_result = [&] {
         LOCK(::cs_main);
         if (txns.size() > 1) return ProcessNewPackage(chainstate, mempool, txns, /* test_accept */ true);
         return PackageMempoolAcceptResult(txns[0]->GetWitnessHash(),
-               AcceptToMemoryPool(chainstate, mempool, txns[0], /* bypass_limits */ false, /* test_accept*/ true));
+               chainman.ProcessTransaction(txns[0], /*test_accept=*/ true));
     }();
 
     UniValue rpc_result(UniValue::VARR);