fix(linking): Match proxies properly

[in03]

Now using link_proxies_with_mpi through Celery by encoding MPI reference as string. Added find_and_link_proxies as backup option if linking with MPI fails.

• fix(linking): Use 'link_with_mpi' post-encode
• fix(link_with_mpi): Add prompt_requeue opt arg
• fix(linking): Assert 0 proxies remain post-encode
• refactor: Update version_constraint_key
• fix(linking): Fail fast if not proxy_media_path
• fix(linking): prevent pre-linking all
• fix(linking): Fix incorrect proxy output extension
• fix(linking): Fix shallow-copy loophole
• refactor: Update version_constraint_key
• fix(linking): Iterate and remove skipping items
• refactor: Update version_constraint_key
• feat(linking): Add prompt_reiterate option
• refactor(linking): Quick filter with linkable type
• refactor: Update version_constraint_key
• perf(queue): Use zip to iterate two lists at once
• fix(handlers): restored reverse list sort
• refactor: Update version_constraint_key
• fix(linking): Catch TypeError if project change
• feat(linking): Add prompt_reiterate option