[TabResumption][ASH] A new field trial param |fetch_history_backend|

Adds a new field trial param |fetch_history_backend| that, if enabled,
fetches suggestion entries from history url ranking backend. This will
replace the existing feature flag #app-info-tab-resumption-module.
The flag will be repurposed to control the visibility of the app info
on UI, not the history backend interaction.

Bug: crbug/337858147, crbug/341124479
Change-Id: Iba5945d579033ebb287cc23f6d51f32e3a8af1d3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5605863


Commit-Queue: Jinsuk Kim <jinsukkim@chromium.org>
Reviewed-by: Xi Han <hanxi@chromium.org>
Code-Coverage: findit-for-me@appspot.gserviceaccount.com <findit-for-me@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/heads/main@{#1311726}