Implement annotation validation (#9673)

* Add validation to all annotations

* Add annotation validation for fcgi

* Fix reviews and fcgi e2e

* Add flag to disable cross namespace validation

* Add risk, flag for validation, tests

* Add missing formating

* Enable validation by default on tests

* Test validation flag

* remove ajp from list

* Finalize validation changes

* Add validations to CI

* Update helm docs

* Fix code review

* Use a better name for annotation risk

docs/user-guide/cli-arguments.md

@@ -15,6 +15,7 @@ They are set in the container spec of the `ingress-nginx-controller` Deployment
 | `--default-backend-service`        | Service used to serve HTTP requests not matching any known server name (catch-all). Takes the form "namespace/name". The controller configures NGINX to forward requests to the first port of this Service. |
 | `--default-server-port`            | Port to use for exposing the default server (catch-all). (default 8181) |
 | `--default-ssl-certificate`        | Secret containing a SSL certificate to be used by the default HTTPS server (catch-all). Takes the form "namespace/name". |
+| `--enable-annotation-validation`  | If true, will enable the annotation validation feature. This value will be defaulted to true on a future release. |
 | `--disable-catch-all`              | Disable support for catch-all Ingresses. (default false) |
 | `--disable-full-test` | Disable full test of all merged ingresses at the admission stage and tests the template of the ingress being created or updated  (full test of all ingresses is enabled by default). |
 | `--disable-svc-external-name` | Disable support for Services of type ExternalName. (default false) |