What does this MR do?
It adds a new gitlab:users:clear_all_authentication_tokens task that clear all the users' authentication tokens.
Are there points in the code the reviewer needs to double check?
I've chosen the simplest approach possible, as suggested by @jacobvosmaer-gitlab and @yorickpeterse in https://gitlab.com/gitlab-org/gitlab-ce/issues/22537#note_16528989.
Why was this MR needed?
We will need it to provide proper mitigation steps for #22537 (closed).
Does this MR meet the acceptance criteria?
CHANGELOG entry added
API support added
Added for this feature/bug
All builds are passing
Conform by the merge request performance guides
Conform by the style guides
Branch has no merge conflicts with
master(if it does - rebase it please)
Squashed related commits together
What are the relevant issue numbers?
Part of #22537 (closed).