Merge bitcoin/bitcoin#19521: Coinstats Index

5f96d7d22d rpc: gettxoutsetinfo rejects hash_serialized_2 for specific height (Fabian Jahr)
23fe50436b test: Add test for coinstatsindex behavior in reorgs (Fabian Jahr)
90c966b0f3 rpc: Allow gettxoutsetinfo and getblockstats for stale blocks (Fabian Jahr)
b9362392ae index, rpc: Add use_index option for gettxoutsetinfo (Fabian Jahr)
bb7788b121 test: Test coinstatsindex robustness across restarts (Fabian Jahr)
e0938c2909 test: Add tests for block_info in gettxoutsetinfo (Fabian Jahr)
2501576ecc rpc, index: Add verbose amounts tracking to Coinstats index (Fabian Jahr)
655d929836 test: add coinstatsindex getindexinfo coverage, improve current tests (Jon Atack)
ca01bb8d68 rpc: Add Coinstats index to getindexinfo (Fabian Jahr)
57a026c30f test: Add unit test for Coinstats index (Fabian Jahr)
6a4c0c09ab test: Add functional test for Coinstats index (Fabian Jahr)
3f166ecc12 rpc: gettxoutsetinfo can be requested for specific blockheights (Fabian Jahr)
3c914d58ff index: Coinstats index can be activated with command line flag (Fabian Jahr)
dd58a4de21 index: Add Coinstats index (Fabian Jahr)
a8a46c4b3c refactor: Simplify ApplyStats and ApplyHash (Fabian Jahr)
9c8a265fd2 refactor: Pass hash_type to CoinsStats in stats object (Fabian Jahr)
2e2648a902 crypto: Make MuHash Remove method efficient (Fabian Jahr)

Pull request description:

  This is part of the coinstats index project tracked in #18000

  While the review of the new UTXO set hash algorithm (MuHash) takes longer recently #19328 was merged which added the possibility to run `gettxoutsetinfo` with a specific hash type. As the first type it added `hash_type=none` which skips the hashing of the UTXO set altogether. This alone did not make `gettxoutsetinfo` much faster but it allows the use of an index for the remaining coin statistics even before a new hashing algorithm has been added. Credit to Sjors for the idea to take this intermediate step.

  Features summary:
  - Users can start their node with the option `-coinstatsindex` which syncs the index in the background
  - After the index is synced the user can  use `gettxoutsetinfo` with `hash_type=none` or `hash_type=muhash` and will get the response instantly out of the index
  - The user can specify a height or block hash when calling `gettxoutsetinfo` to see coin statistics at a specific block height

ACKs for top commit:
  Sjors:
    re-tACK 5f96d7d22d
  jonatack:
    Code review re-ACK 5f96d7d22d per `git range-diff 13d27b4 07201d3 5f96d7d`
  promag:
    Tested ACK 5f96d7d22d. Light code review ACK 5f96d7d22d.

Tree-SHA512: cbca78bee8e9605c19da4fbcd184625fb280200718396c694a56c7daab6f44ad23ca9fb5456d09f245d8b8d9659fdc2b3f3ce5e953c1c6cf4003dbc74c0463c2

src/validation.h

@@ -79,6 +79,7 @@ static const int DEFAULT_SCRIPTCHECK_THREADS = 0;
 static const int64_t DEFAULT_MAX_TIP_AGE = 24 * 60 * 60;
 static const bool DEFAULT_CHECKPOINTS_ENABLED = true;
 static const bool DEFAULT_TXINDEX = false;
+static constexpr bool DEFAULT_COINSTATSINDEX{false};
 static const char* const DEFAULT_BLOCKFILTERINDEX = "0";
 /** Default for -persistmempool */
 static const bool DEFAULT_PERSIST_MEMPOOL = true;