[omnibox] Add 'de' and 'zh-CN' files; fix translation expectations

This CL adds placeholder .xtb files for 'de' and 'zh-CN', with
appropriate hooks in the .grd file. Pedal synonyms translation
expectations (.pyl) language list is also updated to reflect the
latest expectations. Existing placeholder .xtb files are kept so
as to not disrupt in-process translation requests.

Bug: 893183, 1224679
Change-Id: I97b56707bd30130cf8b87616302d0ef1b762f0e1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3052576


Commit-Queue: Orin Jaworski <orinj@chromium.org>
Reviewed-by: Angela Yoeurng <yoangela@chromium.org>
Reviewed-by: Samuel Huang <huangs@chromium.org>
Cr-Commit-Position: refs/heads/master@{#906352}