[FLEDGE] Perform filtering in AuctionRunner.

This will be needed for multi-seller auctions, where the filtering
will need to be applied to multiple sellers and multiple lists of
buyers, and the original AuctionConfig shouldn't be modified, so as not
to expose the results of the filtering directly to worklets, which
could potentially be used to help fingerprint users.

Bug: 1288865
Change-Id: I745182d9ecec0d08a0fdf4837a40756496935a51
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3407895


Reviewed-by: Maks Orlovich <morlovich@chromium.org>
Commit-Queue: Matt Menke <mmenke@chromium.org>
Cr-Commit-Position: refs/heads/main@{#962537}