test: enable functional tests with large rpc args for cli

Also, the following tests (for which self.supports_cli = False was not
set) will now work with --usecli:

feature_fastprune.py
feature_fee_estimation.py
feature_reindex_readonly.py
feature_taproot.py
mempool_package_rbf.py
p2p_net_deadlock.py
p2p_tx_download.py
rpc_packages.py

test/functional/p2p_segwit.py

@@ -221,7 +221,6 @@ class SegWitTest(BitcoinTestFramework):
             ["-acceptnonstdtxn=1", f"-testactivationheight=segwit@{SEGWIT_HEIGHT}", "-par=1"],
             ["-acceptnonstdtxn=0", f"-testactivationheight=segwit@{SEGWIT_HEIGHT}"],
         ]
-        self.supports_cli = False
 
     # Helper functions