Remove controller, actions, and job class fields from Marginalia

Following !55564 (merged), which added endpoint_id, we don't need these other fields.

Example from pg_stat_statements for a mailer:

userid              | 10
dbid                | 16479
queryid             | -5194326892731130503
query               | INSERT INTO "sent_notifications" ("project_id", "noteable_id", "noteable_type", "recipient_id", "reply_key") VALUES ($1, $2, $3, $4, $5) RETURNING "id" /*application:sidekiq,jid:bf4d7528-b30e-4731-a220-98ce6495a32a,endpoint_id:ActionMailer::MailDeliveryJob,line:/lib/gitlab/database.rb:342:in `block in transaction'*/