Implement ES6 export module

[nikita-lobkov]

Hello.
Angular 10 show a warning for every dependency that is imported in ES5. From now, angular require ES6 module to optimize build process.

More info here:
https://angular.io/guide/build#configuring-commonjs-dependencies

Gql-query-builder show warning like this:
my-service.ts depends on 'gql-query-builder'. CommonJS or AMD dependencies can cause optimization bailouts.

Can this cool stuff for sure have ES6 export module as well within current commonJS?

Thanks and have a great day:)

[atulmy]

@nikita-lobkov thanks for identifying the warning. Please feel free to submit a PR, I'll quickly look into it.