[Power Bookmarks] Add tag searching and filtering functionality

This patch adds search functionality to power bookmarks that includes
tag search and filtering. The base of the searching logic is copied
from bookmark_utils and extended in power_bookmark_utils. Several
classes and structures have been exposed that were previously behind
an anonymous namespace to support this.

Tests have also been added for this new functionality.

Bug: 1227831
Change-Id: I84078df1f8a26787121e0792b1db687a9c72de4e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3101387


Reviewed-by: Brandon Wylie <wylieb@chromium.org>
Reviewed-by: Filip Gorski <fgorski@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Matt Jones <mdjones@chromium.org>
Cr-Commit-Position: refs/heads/main@{#914748}