Finalize BackfillResourceStateEventsNamespaceId BBM

What does this MR do and why?

Finalize migration as it has finished in .com with the exception of two small batches. Improvements added to the BBM queries so they can finish correctly.

DB queries

Epic update query

• Before https://console.postgres.ai/gitlab/gitlab-production-main/sessions/41775/commands/128197
• After https://console.postgres.ai/gitlab/gitlab-production-main/sessions/41775/commands/128210

Issue query update

• Before https://console.postgres.ai/gitlab/gitlab-production-main/sessions/41092/commands/126342
• After https://console.postgres.ai/gitlab/gitlab-production-main/sessions/41812/commands/128310

Merge request related records

• Before https://console.postgres.ai/gitlab/gitlab-production-main/sessions/41092/commands/126343
• After https://console.postgres.ai/gitlab/gitlab-production-main/sessions/41812/commands/128311

MR acceptance checklist

Evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Related to #514592 (closed)