feat: Add initial AuthzQuerier implementation (#5919)

feat: Add initial AuthzQuerier implementation
- Adds package database/dbauthz that adds a database.Store implementation where each method goes through AuthZ checks
- Implements all database.Store methods on AuthzQuerier
- Updates and fixes unit tests where required
- Updates coderd initialization to use AuthzQuerier if codersdk.ExperimentAuthzQuerier is enabled

coderd/roles.go

@@ -47,7 +47,7 @@ func (api *API) assignableOrgRoles(rw http.ResponseWriter, r *http.Request) {
 	actorRoles := httpmw.UserAuthorization(r)
 
 	if !api.Authorize(r, rbac.ActionRead, rbac.ResourceOrgRoleAssignment.InOrg(organization.ID)) {
-		httpapi.Forbidden(rw)
+		httpapi.ResourceNotFound(rw)
 		return
 	}