Fixes #550

[accounts/ui][templates] page/message for supervision revokation (supervisee yearly revalidation notification)

[ui][views/registration-templates] add quick link accept for new supervisor for already valid supervisee

[accounts][views] implement rejection endpoint and notify supervisor of revalidation through quick link

[accounts][management][commands] Generate temporary url through model manager for yearly account revalidation

for newly created users

Fixes #542

Fix parallel testing on ci

See merge request !330

These will return the paths based on whether it's a CI run
or a standard run.

Refactor update creation api

See merge request !327

The original logic would get the first item of the experiment name
which matches the user name. However, the name variable in that case
contains the name of the fork, not the fully qualified name. To fix
that, directly use the username variable.