User delete api endpoint

[JasonLovesDoggo]

replace ability to send a DELETE request to v3 obj single (e.g. DELETE /api/v3/obj/user/single/JasonLovesDoggo?lookup=username) with proper deletion functionality.
https://discord.com/channels/861455612093530162/1118723959194648586/1196208344067743884

1. Scrub user data (bio/grad year etc...)
2. set is_active to False
3. return 204

[JasonLovesDoggo]

current options are.

"send post request then deleted?"
"send post request then send email to confirm"
"send post request then "deleted in 30 days"

[JasonLovesDoggo]

all that is really left is the templates being written (by @nelimalu) and then frontend/app adding the endpoint to their code.

as well, there should be a restriction for new usernames that they cannot start with deleted

[JasonLovesDoggo]

oh and api now needs to return is_deleted as well, which I will do