Merge bitcoin/bitcoin#26076: Switch hardened derivation marker to h

fe49f06c0e doc: clarify PR 26076 release note (Sjors Provoost)
bd13dc2f46 Switch hardened derivation marker to h in descriptors (Sjors Provoost)

Pull request description:

  This makes it easier to handle descriptor strings manually, especially when importing from another Bitcoin Core wallet.

  For example the `importdescriptors` RPC call is easiest to use `h` as the marker: `'["desc": ".../0h/..."]'`, avoiding the need for escape characters. With this change `listdescriptors` will use `h`, so you can copy-paste the result, without having to add escape characters or switch `'` to 'h' manually.

  Both markers can still be parsed.

  The `hdkeypath` field in `getaddressinfo` is also impacted by this change, except for legacy wallets. The latter is to prevent accidentally breaking ancient software that uses our legacy wallet.

  See discussion in #15740

ACKs for top commit:
  achow101:
    ACK fe49f06c0e
  darosior:
    re-ACK fe49f06c0e

Tree-SHA512: f78bc873b24a6f7a2bf38f5dd58f2b723e35e6b10e4d65c36ec300e2d362d475eeca6e5afa04b3037ab4bee0bf8ebc93ea5fc18102a2111d3d88fc873c08dc89

test/functional/wallet_listdescriptors.py

@@ -65,7 +65,7 @@ class ListDescriptorsTest(BitcoinTestFramework):
         self.log.info('Test descriptors with hardened derivations are listed in importable form.')
         xprv = 'tprv8ZgxMBicQKsPeuVhWwi6wuMQGfPKi9Li5GtX35jVNknACgqe3CY4g5xgkfDDJcmtF7o1QnxWDRYw4H5P26PXq7sbcUkEqeR4fg3Kxp2tigg'
         xpub_acc = 'tpubDCMVLhErorrAGfApiJSJzEKwqeaf2z3NrkVMxgYQjZLzMjXMBeRw2muGNYbvaekAE8rUFLftyEar4LdrG2wXyyTJQZ26zptmeTEjPTaATts'
-        hardened_path = '/84\'/1\'/0\''
+        hardened_path = '/84h/1h/0h'
         wallet = node.get_wallet_rpc('w2')
         wallet.importdescriptors([{
             'desc': descsum_create('wpkh(' + xprv + hardened_path + '/0/*)'),