Geo: prevent Gitlab::Git::Repository::NoRepository from stucking replication

What does this MR do?

• Improves log messages for NoRepository exception
• Implements cache invalidation when NoRepository exception is detected

Are there points in the code the reviewer needs to double check?

Why was this MR needed?

After some unknown steps the replication can get stuck if one repository is marked as non-empty but is actually not created.

See #2635 (closed)

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• API support added
• Tests
  • Added for this feature/bug
  • All builds are passing
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if it does - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?

Closes #2635 (closed)