net: Use mockable time for ping/pong, add tests

test/functional/feature_bip68_sequence.py

@@ -30,7 +30,10 @@ class BIP68Test(BitcoinTestFramework):
     def set_test_params(self):
         self.num_nodes = 2
         self.extra_args = [
-            ["-acceptnonstdtxn=1"],
+            [
+                "-acceptnonstdtxn=1",
+                "-peertimeout=9999",  # bump because mocktime might cause a disconnect otherwise
+            ],
             ["-acceptnonstdtxn=0"],
         ]