Change each workaround from a simple bool to a struct with info
including name, workaround set, description, and bug IDs. This will help
with future workaround integration with Chrome.

Bug: angleproject:1621
Change-Id: Ia27c180abaf845e280060c803e5994cc3152a057
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1593917
Commit-Queue: Jonah Ryan-Davis <jonahr@google.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>