[webui] Add polymer3 to //ui/webui/resources::code_cache_resources

Specifically this generates and integrates the code cache resources
for polymer_bundled.min.js (which is generated and checked-in to the
repo).

Use of polymer3 is deprecated, however there are some existing
WebUIs that may benefit from the build-time bytecode optimization
during experimentation, namely:

  - chrome://history-clusters-side-panel.top-chrome
  - chrome://bookmarks-side-panel.top-chrome
  - chrome://shopping-insights-side-panel.top-chrome

Bug: 378504039
Change-Id: Iececdc0b092079f11c2b63cd56e6c267a8cf0416
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6345090
Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Commit-Queue: Tom Lukaszewicz <tluk@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1431139}