feat(coderd): add ability to search org members by user_id, is_system, github_user_id (#20048)

Adds the ability to search org members by query.
Supported fields: `user_id`, `is_system`, `github_user_id`.

coderd/users.go

@@ -1236,6 +1236,7 @@ func (api *API) userRoles(rw http.ResponseWriter, r *http.Request) {
 		UserID:         user.ID,
 		OrganizationID: uuid.Nil,
 		IncludeSystem:  false,
+		GithubUserID:   0,
 	})
 	if err != nil {
 		httpapi.Write(ctx, rw, http.StatusInternalServerError, codersdk.Response{