[Downstream] VPP Main heap stats

This commit includes series of upstream patches squashed:
- https://gerrit.fd.io/r/c/vpp/+/31678
- https://gerrit.fd.io/r/c/vpp/+/31636
- https://gerrit.fd.io/r/c/vpp/+/31636

Also, in respect to new statistics layout, basic counter verification
test has been changed.

This commit also excludes vpp-patches/.. files to be processed
during checkstyle analysis.

hack/checkstyle.sh

@@ -39,7 +39,7 @@ done
 if [ "${FULL}" == "1" ]; then
 	FILELIST=$(git ls-tree -r HEAD --name-only)
 else
-	FILELIST=$((git diff HEAD~1.. --name-only; git ls-files -m ) | sort -u)
+	FILELIST=$((git diff HEAD~1.. --name-only; git ls-files -m ) | sort -u | egrep -v vpp-patches)
 fi
 
 # Check to make sure we have indent.  Exit if we don't with an error message, but

upf/test/test_upf.py

@@ -541,13 +541,13 @@ def send_from_sgi_to_ue(self, payload=None, l4proto=UDP, ue_port=12345,
 
     def verify_upg_counters(self, expected_assoc=0, expected_sessions=0,
                             expected_flows=0):
-        flow_counter = self.statistics.dump(self.statistics.ls('/upf/total_flows'))
-        session_counter = self.statistics.dump(self.statistics.ls('/upf/total_sessions'))
-        association_counter = self.statistics.dump(self.statistics.ls('/upf/total_assoc'))
+        flow_counter = self.statistics['/upf/total_flows']
+        session_counter = self.statistics['/upf/total_sessions']
+        association_counter = self.statistics['/upf/total_assoc']
         # Counter dir is implemented as a per-cpu vector of vectors
-        self.assertEqual(flow_counter['/upf/total_flows'][0][0], expected_flows)
-        self.assertEqual(session_counter['/upf/total_sessions'][0][0], expected_sessions)
-        self.assertEqual(association_counter['/upf/total_assoc'][0][0], expected_assoc)
+        self.assertEqual(flow_counter[0][0], expected_flows)
+        self.assertEqual(session_counter[0][0], expected_sessions)
+        self.assertEqual(association_counter[0][0], expected_assoc)
 
 class TestTDFBase(PFCPHelper):
     """Base TDF Test"""