Merge #19953: Implement BIP 340-342 validation (Schnorr/taproot/tapscript)

0e2a5e448f tests: dumping and minimizing of script assets data (Pieter Wuille)
4567ba034c tests: add generic qa-asset-based script verification unit test (Pieter Wuille)
f06e6d0345 tests: functional tests for Schnorr/Taproot/Tapscript (Pieter Wuille)
3c226639eb tests: add BIP340 Schnorr signature support to test framework (Pieter Wuille)
206fb180ec --- [TAPROOT] Tests --- (Pieter Wuille)
d7ff237f29 Activate Taproot/Tapscript on regtest (BIP 341, BIP 342) (Pieter Wuille)
e9a021d7e6 Make Taproot spends standard + policy limits (Pieter Wuille)
865d2c37e2 --- [TAPROOT] Regtest activation and policy --- (Pieter Wuille)
72422ce396 Implement Tapscript script validation rules (BIP 342) (Johnson Lau)
330de894a9 Use ScriptExecutionData to pass through annex hash (Pieter Wuille)
8bbed4b7ac Implement Taproot validation (BIP 341) (Pieter Wuille)
0664f5fe1f Support for Schnorr signatures and integration in SignatureCheckers (BIP 340) (Pieter Wuille)
5de246ca81 Implement Taproot signature hashing (BIP 341) (Johnson Lau)
9eb590894f Add TaggedHash function (BIP 340) (Pieter Wuille)
450d2b2371 --- [TAPROOT] BIP340/341/342 consensus rules --- (Pieter Wuille)
5d62e3a68b refactor: keep spent outputs in PrecomputedTransactionData (Pieter Wuille)
8bd2b4e784 refactor: rename scriptPubKey in VerifyWitnessProgram to exec_script (Pieter Wuille)
107b57df9f scripted-diff: put ECDSA in name of signature functions (Pieter Wuille)
f8c099e220 --- [TAPROOT] Refactors --- (Pieter Wuille)

Pull request description:

  This is an implementation of the Schnorr/taproot consensus rules proposed by BIPs [340](https://github.com/bitcoin/bips/blob/master/bip-0340.mediawiki), [341](https://github.com/bitcoin/bips/blob/master/bip-0340.mediawiki), and [342](https://github.com/bitcoin/bips/blob/master/bip-0340.mediawiki).

  See the list of commits [below](https://github.com/bitcoin/bitcoin/pull/19953#issuecomment-691815830). No signing or wallet support of any kind is included, as testing is done entirely through the Python test framework.

  This is a successor to https://github.com/bitcoin/bitcoin/pull/17977 (see discussion following [this comment](https://github.com/bitcoin/bitcoin/pull/17977#issuecomment-682285983)), and will have further changes squashed/rebased. The history of this PR can be found in #19997.

ACKs for top commit:
  instagibbs:
    reACK 0e2a5e448f
  benthecarman:
    reACK 0e2a5e4
  kallewoof:
    reACK 0e2a5e448f
  jonasnick:
    ACK 0e2a5e448f almost only looked at bip340/libsecp related code
  jonatack:
    ACK 0e2a5e448f modulo the last four commits (tests) that I plan to finish reviewing tomorrow
  fjahr:
    reACK 0e2a5e448f
  achow101:
    ACK 0e2a5e448f

Tree-SHA512: 1b00314450a2938a22bccbb4e177230cf08bd365d72055f9d526891f334b364c997e260c10bc19ca78440b6767712c9feea7faad9a1045dd51a5b96f7ca8146e

test/functional/test_runner.py

@@ -70,6 +70,7 @@ TEST_FRAMEWORK_MODULES = [
     "address",
     "blocktools",
     "muhash",
+    "key",
     "script",
     "segwit_addr",
     "util",
@@ -107,6 +108,7 @@ BASE_SCRIPTS = [
     'mempool_updatefromblock.py',
     'wallet_dump.py',
     'wallet_listtransactions.py',
+    'feature_taproot.py',
     # vv Tests less than 60s vv
     'p2p_sendheaders.py',
     'wallet_importmulti.py',