Move Filtering Result enum to Supervised Users Utils

This is a pre-requisite for moving SU preferences
registration to the SU preferences library.
Moving the Filtering result enum to
SU utils package (from components/su/c/b to su/c/c),
is needed, as consuming the enum in the SU
pref library would result in circular dependencies.

This change is a refactoring of
existing enum. I does not have any functional impact
on the affected consumers.

Low-Coverage-Reason: LARGE_SCALE_REFACTOR
Bug: b/306376651
Change-Id: Ifa4ab0f5176ac8f4842067f65b7f4302278c5082
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4984151
Reviewed-by: Sylvain Defresne <sdefresne@chromium.org>
Commit-Queue: Anthi Orfanou <anthie@google.com>
Reviewed-by: Alex Ilin <alexilin@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1220296}