Migrate Redis keys in RepositoryCache to the structured format

Everyone can contribute. Help move this issue forward while earning points, leveling up and collecting rewards.

• Collaborate/take over this issue

• Epic: &9313
• Discussion: #378189 (comment 1166190924)

RepositoryCache is responsible for majority of repository related caches (branches, tags, avatars, ...)

Proposal

Update all cache_method keys to follow the new format:

Example

cache:gitlab:source_code_management:Repository#has_ambiguous_refs?:project-1

Notes

• source_code_management can be a default value, because the whole RepositoryCache belongs to source_code_management feature category.
• We keep cache:gitlab for now, the migration to gl: will take place after.