[Extensions][web_accessible_resources] Parse MV3 for resources.

In Manifest V3, extensions will have finer grained control over
web-accessible resources, with the ability to restrict embedding to
specific URL patterns or extension IDs. This CL introduces the
parsing for a new format in the manifest.json to support taking a
list of objects, rather than a list of strings:

"web_accessible_resources": [
  {
    “resources”: [“file.gif”],
    “matches”: [*://*.chromium.org/*],
    “extension_ids”: [“abcdefghijklmnopabcdefghijklmnop”]
  }
]

This CL only parses and stores matches and ids alongside resources.
Permission checking based on those two fields to be done subsequently.

Bug: 1133624e

Change-Id: Ice0374d4de433d23700a6c7b03ff3d76cd0bd9fd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2439795


Commit-Queue: Solomon Kinard <solomonkinard@chromium.org>
Reviewed-by: Devlin <rdevlin.cronin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#824315}