Add problemMatcher definitions

Author: janjongboom

tools/export/vscode/tasks.tmpl

@@ -6,5 +6,17 @@
     "command": "make",
     "isShellCommand": true,
     "args": ["-j"],
-    "showOutput": "always"
-}
+    "showOutput": "always",
+    "problemMatcher": {
+        "owner": "cpp",
+        "fileLocation": ["relative", "${workspaceRoot}/mbed-os"],
+        "pattern": {
+            "regexp": "^(.*):(\\d+):(\\d+):\\s+(warning|error):\\s+(.*)$",
+            "file": 1,
+            "line": 2,
+            "column": 3,
+            "severity": 4,
+            "message": 5
+        }
+    }
+}