Add Ci::RetryBridgeService and Mutation to GQL

What does this MR do and why?

This is the backend component for retrying a bridge job that creates a new downstream pipeline.: #345050 (closed)
It is part of this epic: &6947 (comment 830058603)

• Adds a unified RetryJobService which will retry either a Ci::Bridge or a Ci::Build. This was previously Ci::RetryBuildService.
• Renames all uses of RetryBuildService with the new unified service name, RetryJobService
• Refactors, renames, and reorganizes the RetryJobService spec
• Adds Ci::Bridge specific specs to the RetryJobService spec
• Extracts clone_accessors to their respective classes and removes extra_accessors from Ci::Build
• Replaces uses of Ci::Build.retry with RetryJobService
• Changes the ID type in Job::Base from CiBuildID to CiProcessableID and updates the frontend mutations.
• Adds retryable? to Ci::Processable and removes it from Ci::Bridge
• Returns the new job rather than the old one in the mutation

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.