Remove unused API v2 endpoints add more spectral rules

* Removes /teams and /metrics endpoints that were added but never put into use. Carrying them forward is a maintenance burden that is unnecessary.
* Adds Spectral rules that enforce guidelines around naming of operations, and response structure. They are not perfect but should catch blunt violations.
* Updates endpoint implementations that violated the enforced rules, e.g. by populating Location headers.

Signed-off-by: nscuro <nscuro@protonmail.com>

Author: nscuro