libchrome_tools: uprev: move filter to separate module.

Allow filters module to configure its filter.
This is change is prepared to support generating new history for newly
wanted file after filter change.

BUG=b:180558819
TEST=libchrome_tools/uprev/generate_filtered_tree.py and compare result manually

Change-Id: I5a117d6ed8d1939ffb698edd0d8ef1b9b2d08192
Reviewed-on: https://chromium-review.googlesource.com/c/aosp/platform/external/libchrome/+/2691590
Tested-by: Qijiang Fan <fqj@google.com>
Commit-Queue: Qijiang Fan <fqj@google.com>
Reviewed-by: Hidehiko Abe <hidehiko@chromium.org>