[BUG] The resource_quota API allows taxonomies parameters

[bastian-src]

A Resource Quota is independent of any taxonomies since it is bound to users and usergroups.

However, the API endpoint to update and create a resource quota allows such parameters and does not recognize them as wrong (as it should be the case):

curl --request PUT \
  --url https://<addr>/foreman_resource_quota/api/v2/resource_quotas/1 \
  --header 'Authorization: Basic <auth>' \
  --header 'content-type: application/json' \
  --data '{
  "resource_quota": {
    "name": "testA",
    "organization_id": "1"
  }
}'

→ results in an HTTP 200.

The issue came up during #103.