User module docs and logs

[lyannne]

ℹ️ Issue

Closes #257

📝 Description

1. Added logging and purpose statements to appropriate service methods.
2. Documented routes in swagger.
3. Made request body types in user.types.ts (used a json format so structure of data is clear to anyone testing).
4. Changed change-roles route from POST to PATCH (since nothing is getting created; it's more like a user being moved).

✔️ Verification

N/A (just looked to see everything was there in swagger)

Test Changes

N/A

🏕️ (Optional) Future Work / Notes

A few concerns:

• Should the delete-user route also be changed to DELETE instead of POST? I think that makes more sense, but the route would then need parameters instead of accepting a request body.
• Every controller method has a guard, whether it's a user guard or admin one. This makes testing from the swagger UI kind of impossible. Thoughts?

[prooflesben]

Just make sure the routes work in swagger but everything lgtm(lets get this money).

[yumi520]

lgtm