scripted-diff: test: Replace uses of (dis)?connect_nodes global

-BEGIN VERIFY SCRIPT-

 # max-depth=0 excludes test/functional/test_framework/...
 FILES=$(git grep -l --max-depth 0 "connect_nodes" test/functional)

 # Replace (dis)?connect_nodes(self.nodes[a], b) with self.(dis)?connect_nodes(a, b)
 sed -i 's/\b\(dis\)\?connect_nodes(self\.nodes\[\(.*\)\]/self.\1connect_nodes(\2/g' $FILES

 # Remove imports in the middle of a line
 sed -i 's/\(dis\)\?connect_nodes, //g' $FILES
 sed -i 's/, \(dis\)\?connect_nodes//g' $FILES

 # Remove imports on a line by themselves
 sed -i '/^\s*\(dis\)\?connect_nodes,\?$/d' $FILES
 sed -i '/^from test_framework\.util import connect_nodes$/d' $FILES

-END VERIFY SCRIPT-

Co-authored-by: Elliott Jin <elliott.jin@gmail.com>

test/functional/mempool_persist.py

@@ -45,8 +45,6 @@ from test_framework.util import (
     assert_equal,
     assert_greater_than_or_equal,
     assert_raises_rpc_error,
-    connect_nodes,
-    disconnect_nodes,
 )
 
 
@@ -83,11 +81,11 @@ class MempoolPersistTest(BitcoinTestFramework):
         assert_greater_than_or_equal(tx_creation_time_higher, tx_creation_time)
 
         # disconnect nodes & make a txn that remains in the unbroadcast set.
-        disconnect_nodes(self.nodes[0], 1)
+        self.disconnect_nodes(0, 1)
         assert(len(self.nodes[0].getpeerinfo()) == 0)
         assert(len(self.nodes[0].p2ps) == 0)
         self.nodes[0].sendtoaddress(self.nodes[2].getnewaddress(), Decimal("12"))
-        connect_nodes(self.nodes[0], 2)
+        self.connect_nodes(0, 2)
 
         self.log.debug("Stop-start the nodes. Verify that node0 has the transactions in its mempool and node1 does not. Verify that node2 calculates its balance correctly after loading wallet transactions.")
         self.stop_nodes()