Merge branch 'feature/delete-validator' into 'develop'

Move deletions to the common pipeline

Closes #1497

See merge request pleroma/pleroma!2441

diff --cc lib/pleroma/user.ex
Simple merge

diff --cc lib/pleroma/web/activity_pub/activity_pub.ex
Simple merge

diff --cc lib/pleroma/web/activity_pub/activity_pub_controller.ex
Simple merge

diff --cc lib/pleroma/web/activity_pub/transmogrifier.ex
Simple merge

diff --cc lib/pleroma/web/admin_api/admin_api_controller.ex
Simple merge

diff --cc test/web/activity_pub/activity_pub_test.exs
Simple merge

diff --cc test/web/admin_api/admin_api_controller_test.exs
Simple merge