Drop clusters_applications_cert_managers table

We're cleaning up the deprecated Clusters::Applications code related to Remove clusters_applications_* code (#366573 - closed)

Application code that used this table was removed in Clusters::Applications models removal (#388696 - closed)

In !117460 (merged) we dropped the foreign keys. This was in post deploy migration that has been run.

This MR's purpose is to

• drop the clusters_applications_cert_managers table
• move the dictionary files per these instructions

For transparency, this was originally part of a single MR that drops many clusters_applications* tables, but sensing some concern around this I have split them into individual MRs.

Table usage

Thanos Query showing table usage. It's non-zero but it's so small my guess is that this is something that's not specific to the table. Would love any input on what it could be.

Migration output

main: == [advisory_lock_connection] object_id: 275080, pg_backend_pid: 57103
main: == 20230501180958 DropClustersApplicationsCertManagers: migrating =============
main: -- drop_table(:clusters_applications_cert_managers)
main:    -> 0.0284s
main: == 20230501180958 DropClustersApplicationsCertManagers: migrated (0.0358s) ====

main: == [advisory_lock_connection] object_id: 275080, pg_backend_pid: 57103
ci: == [advisory_lock_connection] object_id: 275280, pg_backend_pid: 57105
ci: == 20230501180958 DropClustersApplicationsCertManagers: migrating =============
ci: -- drop_table(:clusters_applications_cert_managers)
ci:    -> 0.0011s
ci: == 20230501180958 DropClustersApplicationsCertManagers: migrated (0.0144s) ====

ci: == [advisory_lock_connection] object_id: 275280, pg_backend_pid: 57105