script: implement IDBKeyRange (#38268)

#37684 provided the backend for this change. The key range interface
just wraps a `IndexedDBKeyRange` and exposes the methods from it as per
the spec.

Spec: https://www.w3.org/TR/IndexedDB-2/#keyrange
Testing: WPT tests (some regressions have been exposed, but that's fine)

---------

Signed-off-by: Ashwin Naren <arihant2math@gmail.com>
Signed-off-by: Josh Matthews <josh@joshmatthews.net>
Co-authored-by: Josh Matthews <josh@joshmatthews.net>

components/script_bindings/webidls/IDBKeyRange.webidl

@@ -0,0 +1,28 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+/*
+ * The origin of this IDL file is
+ * https://w3c.github.io/IndexedDB/#keyrange
+ *
+ */
+
+// https://w3c.github.io/IndexedDB/#keyrange
+[Pref="dom_indexeddb_enabled", Exposed=(Window,Worker)]
+interface IDBKeyRange {
+  readonly attribute any lower;
+  readonly attribute any upper;
+  readonly attribute boolean lowerOpen;
+  readonly attribute boolean upperOpen;
+
+  // Static construction methods:
+  [Throws, NewObject] static IDBKeyRange only(any value);
+  [Throws, NewObject] static IDBKeyRange lowerBound(any lower, optional boolean open = false);
+  [Throws, NewObject] static IDBKeyRange upperBound(any upper, optional boolean open = false);
+  [Throws, NewObject] static IDBKeyRange bound(any lower,
+                                       any upper,
+                                       optional boolean lowerOpen = false,
+                                       optional boolean upperOpen = false);
+
+  [Throws] boolean _includes(any key);
+};