Merge bitcoin/bitcoin#34911: rpc, mempool: -deprecatedrpc fullrbf and bip125-replaceable from mempool RPCs

8deed0df06 doc: add release notes for PR 34911 (rkrux)
1a85ca1dff rpc, mempool: rpcdeprecate `bip125-replaceable` key in mempool RPCs reponses (rkrux)
f89d18c3b1 rpc, mempool: rpcdeprecate `fullrbf` key in getmempoolinfo RPC response (rkrux)

Pull request description:

  mempoolfullrbf=1 behaviour has been the default since v28 and the argument has
  been removed since v29 subsequently.

  The getmempoolinfo RPC need not return the deprecated `fullrbf` key in the
  response anymore unless the user requests it via -deprecatedrpc=fullrbf node
  argument.

  Also, remove the `bip125-replaceable` key from the mempool RPCs
  responses (because it, too, has been deprecated since v29) unless the user
  requests it via -deprecatedrpc=bip125 node argument.

ACKs for top commit:
  optout21:
    ACK 8deed0df06
  sedited:
    ACK 8deed0df06
  instagibbs:
    ACK 8deed0df06

Tree-SHA512: dfbbdf04ae25dafe81758bd85715af80d736e21bb913ab09ff8fd8225587b7a1bf1dd6b0f7ea05135504e11d43371d98e5f5fc6e3717d581e870e8c2bf97811b

test/functional/feature_rbf.py

@@ -28,6 +28,7 @@ class ReplaceByFeeTest(BitcoinTestFramework):
     def set_test_params(self):
         self.num_nodes = 2
         self.uses_wallet = None
+        self.extra_args = [["-deprecatedrpc=fullrbf", "-deprecatedrpc=bip125"], []]
 
     def run_test(self):
         self.wallet = MiniWallet(self.nodes[0])