feat: add typename insertion functionality to graphql-tag

[dmhalejr]

Aims to close #71

Leveraging the muscle of addTypenameToDocument from the apollo-utilities package to add ability to add __typenames when enabled.

Parameter defined was set as enableTypenameInsertion and disableTypenameInsertion appropriately

The one oddity from my quick feature creation was that the test/graphql-v0.11.js which I didn't touch changed ever so slightly where undefined and null became null and []

I'll change it back but my npm test yielded the same testing compatibility fails/passes as my fresh master fork.

Thanks for all you do! Let me know what else I can do to meet guidelines.

[apollo-cla]

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