URLPattern: Add WPT cases for isolated '.' and '..' in pathname.

This CL adds WPT test cases for the issue described in:

whatwg/urlpattern#156

Note, chromium does not suffer from the bug in the spec and already passes
the tests.

Change-Id: I121fe82bf1cdcb5b0ef6634d51d4f58beb57a2bc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3399610
Reviewed-by: Domenic Denicola <[email protected]>
Commit-Queue: Ben Kelly <[email protected]>
Cr-Commit-Position: refs/heads/main@{#960622}

Author: wanderview

urlpattern/resources/urlpatterntestdata.json

@@ -2665,5 +2665,19 @@
     "pattern": [{ "pathname": "*//*" }],
     "inputs": [{ "pathname": "foo/bar" }],
     "expected_match": null
+  },
+  {
+    "pattern": [{ "pathname": "/:foo." }],
+    "inputs": [{ "pathname": "/bar." }],
+    "expected_match": {
+      "pathname": { "input": "/bar.", "groups": { "foo": "bar" } }
+    }
+  },
+  {
+    "pattern": [{ "pathname": "/:foo.." }],
+    "inputs": [{ "pathname": "/bar.." }],
+    "expected_match": {
+      "pathname": { "input": "/bar..", "groups": { "foo": "bar" } }
+    }
   }
 ]