multi: Add itest for funding timeout

This commit adds an integration test that
verifies the funding timeout behavior in the
funding manager, in dev/integration test.
Signed-off-by: Nishant Bansal <nishant.bansal.282003@gmail.com>

itest/list_on_test.go

@@ -670,6 +670,10 @@ var allTestCases = []*lntest.TestCase{
 		Name:     "fee replacement",
 		TestFunc: testFeeReplacement,
 	},
+	{
+		Name:     "funding manager funding timeout",
+		TestFunc: testFundingManagerFundingTimeout,
+	},
 }
 
 // appendPrefixed is used to add a prefix to each test name in the subtests