[Files]: Adds table for storing file info

Adds a new table that stores file info. File info is stored by the URL
ID. Adds APIs for getting, putting, and deleting file info.

Bug: b:327535200
Change-Id: I9dc6c6e9c15d59eb6db8307f775334527ca077da
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5409883


Reviewed-by: Luciano Pacheco <lucmult@chromium.org>
Commit-Queue: Bo Majewski <majewski@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1282976}