[Passwords] Add structure and header of pass. list in the mngmt bubble

This CL introduces the main structure of the ManagePasswordsView
bubble that will use a PageSwitcherView to switch between the password
list and the password details page.

Since headers are custom since the details bubble will provide a
back button and two icons.

Although the header on the password list bubble is a standard header
with an icon and a text, I would still use SetTitleView() since the
second screen must have a custom title and I don't want to keep
switching between both modes.

Password list mock: http://screen/ACTP2B6KVxHndAJ
Details page mock: http://screen/8zQJYdAGWKMeLBY

Screenshot: http://screen/ArqybuPwFDZBQsV

Bug: 1382017
Change-Id: I21e5e630af299a8487f42f77bee3d0b7577b4bb3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4023293


Reviewed-by: Peter Kasting <pkasting@chromium.org>
Commit-Queue: Mohamed Amir Yosef <mamir@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1071568}