Resolve "Upload migration lease key is incorrect for non-mounted uploaders"

What does this MR do?

Creates lease key based on upload ID instead of model ID for file uploads (precisely for all uploaders which include RecordsUpload which are - FileUploader, AttachmentUploader and AvatarUploader).

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

Why was this MR needed?

For FileUploaders it's possible that a model has many uploads and if lease key is created only from model id, it causes that the model's uploads can not be migrated in parallel because the exclusive lease key would be same for all uploads of the model.

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• API support added
• Tests added for this feature/bug
• Conform by the code review guidelines
  • Has been reviewed by a UX Designer
  • Has been reviewed by a Frontend maintainer
  • Has been reviewed by a Backend maintainer
  • Has been reviewed by a Database specialist
• Conform by the merge request performance guides
• Conform by the style guides
• If you have multiple commits, please combine them into a few logically organized commits by squashing them
• Internationalization required/considered
• End-to-end tests pass (package-and-qa manual pipeline job)

What are the relevant issue numbers?

Closes #47513 (closed)