Componentize chrome/browser/webid

This CL componentizes c/b/webid, as per [1].
The following targets were added:
- //c/b/webid:webid,
- //chrome/browser/webid:impl,
- //chrome/browser/webid:unit_tests
- //chrome/browser/webid:browser_tests.

[1] docs/chrome_browser_design_principles.md

R=dljames@chromium.org

Bug: 353332589
Change-Id: Ib54f671bf75be35e529a6d075fade38e2255903b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6918063
Reviewed-by: Darryl James <dljames@chromium.org>
Commit-Queue: Antonio Gomes <tonikitoo@igalia.com>
Cr-Commit-Position: refs/heads/main@{#1511484}