refactor: Move ChainstateManager options into m_options struct

Move ChainstateManager options into m_options struct to simplify class
initialization, organize class members, and to name external option variables
differently than internal state variables.

This change was originally in bitcoin#25862, but it was suggested to split off in
bitcoin#25862 (comment) so it could
be merged earlier and reduce conflicts with other PRs.

Author: ryanofsky

src/validation.cpp

@@ -3608,7 +3608,7 @@ bool ChainstateManager::AcceptBlockHeader(const CBlockHeader& block, BlockValida
             LogPrint(BCLog::VALIDATION, "%s: %s prev block invalid\n", __func__, hash.ToString());
             return state.Invalid(BlockValidationResult::BLOCK_INVALID_PREV, "bad-prevblk");
         }
-        if (!ContextualCheckBlockHeader(block, state, m_blockman, *this, pindexPrev, m_adjusted_time_callback())) {
+        if (!ContextualCheckBlockHeader(block, state, m_blockman, *this, pindexPrev, m_options.adjusted_time_callback())) {
             LogPrint(BCLog::VALIDATION, "%s: Consensus::ContextualCheckBlockHeader: %s, %s\n", __func__, hash.ToString(), state.ToString());
             return false;
         }

src/validation.h

@@ -838,10 +838,6 @@ class ChainstateManager
 
     CBlockIndex* m_best_invalid GUARDED_BY(::cs_main){nullptr};
 
-    const CChainParams m_chainparams;
-
-    const std::function<NodeClock::time_point()> m_adjusted_time_callback;
-
     //! Internal helper for ActivateSnapshot().
     [[nodiscard]] bool PopulateAndValidateSnapshot(
         CChainState& snapshot_chainstate,
@@ -861,12 +857,13 @@ class ChainstateManager
 public:
     using Options = kernel::ChainstateManagerOpts;
 
-    explicit ChainstateManager(const Options& opts)
-        : m_chainparams{opts.chainparams},
-          m_adjusted_time_callback{Assert(opts.adjusted_time_callback)} {};
+    explicit ChainstateManager(Options options) : m_options{std::move(options)}
+    {
+        Assert(m_options.adjusted_time_callback);
+    }
 
-    const CChainParams& GetParams() const { return m_chainparams; }
-    const Consensus::Params& GetConsensus() const { return m_chainparams.GetConsensus(); }
+    const CChainParams& GetParams() const { return m_options.chainparams; }
+    const Consensus::Params& GetConsensus() const { return m_options.chainparams.GetConsensus(); }
 
     /**
      * Alias for ::cs_main.
@@ -881,6 +878,7 @@ class ChainstateManager
      */
     RecursiveMutex& GetMutex() const LOCK_RETURNED(::cs_main) { return ::cs_main; }
 
+    const Options m_options;
     std::thread m_load_block;
     //! A single BlockManager instance is shared across each constructed
     //! chainstate to avoid duplicating block metadata.