upgrade graphql-tools to v6 (#6701)

* upgrade to v6

* remove old graphql-tools package

Co-authored-by: Antonio Davi Macedo Coelho de Castro <adavimacedo@gmail.com>

src/GraphQL/loaders/schemaDirectives.js

@@ -1,5 +1,5 @@
 import gql from 'graphql-tag';
-import { SchemaDirectiveVisitor } from 'graphql-tools';
+import { SchemaDirectiveVisitor } from '@graphql-tools/utils';
 import { FunctionsRouter } from '../../Routers/FunctionsRouter';
 
 export const definitions = gql`