chore: expand storage middleware init func with cleanup callback

What does this MR do?

This MR expands storage driver initialisation function to allow for returning clean-up callback that we can call during container-registry shutdown.

The change is a prerequisite, and was expanded from !2352 (merged)

Related to #1565 (closed)

Author checklist

• Assign one of conventional-commit prefixes to the MR.
  • fix: Indicates a bug fix, triggers a patch release.
  • feat: Signals the introduction of a new feature, triggers a minor release.
  • perf: Focuses on performance improvements that don't introduce new features or fix bugs, triggers a patch release.
  • docs: Updates or changes to documentation. Does not trigger a release.
  • style: Changes that do not affect the code's functionality. Does not trigger a release.
  • refactor: Modifications to the code that do not fix bugs or add features but improve code structure or readability. Does not trigger a release.
  • test: Changes related to adding or modifying tests. Does not trigger a release.
  • chore: Routine tasks that don't affect the application, such as updating build processes, package manager configs, etc. Does not trigger a release.
  • build: Changes that affect the build system or external dependencies. May trigger a release.
  • ci: Modifications to continuous integration configuration files and scripts. Does not trigger a release.
  • revert: Reverts a previous commit. It could result in a patch, minor, or major release.
• Feature flags
  • This change does not require a feature flag
  • Added feature flag: ( Add the Feature flag tracking issue link here )
• Unit-tests
  • Unit-tests are not required
  • I added unit tests
• Documentation:
  • Documentation is not required
  • I added documentation
  • I created or linked to an existing issue for every added or updated TODO, BUG, FIXME or OPTIMIZE prefixed comment
• database changes including schema/background migrations:
  • Change does not introduce database changes
  • MR includes DB chagnes
    • Do not include code that depends on the schema migrations in the same commit. Split the MR into two or more.
    • Do not include code that depends on background migrations in the same release.
    • Manually run up and down migrations in a postgres.ai production database clone and post a screenshot of the result here.
    • If adding new schema migrations make sure the REGISTRY_SELF_MANAGED_RELEASE_VERSION CI variable in migrate.yml is pointing to the latest GitLab self-managed released registry version. Find the correct registry version here. Make sure to select the branch of the latest GitLab release.
    • If adding new queries, extract a query plan from postgres.ai and post the link here. If changing existing queries, also extract a query plan for the current version for comparison.
      • I do not have access to postgres.ai and have made a comment on this MR asking for these to be run on my behalf.
    • If adding new background migration, follow the guide for performance testing new background migrations and add a report/summary to the MR with your analysis.
• Ensured this change is safe to deploy to individual stages in the same environment (cny -> prod). State-related changes can be troublesome due to having parts of the fleet processing (possibly related) requests in different ways.
• If the change contains a breaking change, apply the breaking change label.
• If the change is considered high risk, apply the label high-risk-change
• Changes cannot be rolled back
  • Change can be safelly rolled back
  • Change can't be safelly rolled back
    • Apply the label cannot-rollback.
    • Add a section to the MR description that includes the following details:
      • The reasoning behind why a release containing the presented MR can not be rolled back (e.g. schema migrations or changes to the FS structure)
      • Detailed steps to revert/disable a feature introduced by the same change where a migration cannot be rolled back. (note: ideally MRs containing schema migrations should not contain feature changes.)
      • Ensure this MR does not add code that depends on these changes that cannot be rolled back.

Documentation/resources

Code review guidelines

Go Style guidelines

Reviewer checklist

• Ensure the commit and MR tittle are still accurate.
• If the change contains a breaking change, verify the breaking change label.
• If the change is considered high risk, verify the label high-risk-change
• Identify if the change can be rolled back safely. (note: all other reasons for not being able to rollback will be sufficiently captured by major version changes).