Make suffix of generated query response types customizable

[jlkiri]

This PR addresses the following issue: #2110

I made changes to base-documents-visitor that allow users to specify (via config) a custom suffix of generated operation result type names (like PlayerQuery or PlayerMutation types). Adding a suffix Result to e.g. PlayerQuery type would generate PlayerQueryResult.

To add a suffix (which type is string), you have to use operationResultSuffix in config.yml.

[dotansimha]

Hi @jlkiri !
Thank you.
I think you should allow other base plugins to know about this new flag as well.
The typescript-react-apollo (based on base-client-side-visitor) is using the generated type name, so it might cause a mismatch if it won't append this suffix as well.

[jlkiri]

As far as I could understand, base-client-side-visitor is the only one I had to additionally change. I also added an annotation.

[dotansimha]

Looks great, thanks @jlkiri !