self_upload utility alias

BUR #14596 has been approved by @nonamethanks.

create alias self_upload -> self-upload

self-upload is a relatively common mistag, plus all grammar and styling guides state that "self-*" compounds must be hyphenated.

BUR #14597 has been rejected.

create alias self-upload -> self_upload

Reverse alias in case we want to keep the old one

No point in the latter BUR given that self-upload will autocomplete to self_upload thanks to the new(ish) system. It would probably be rejected.

The bulk update request #14596 (forum #231106) has been approved by @nonamethanks.

The bulk update request #14597 (forum #231107) has been rejected by @nonamethanks.