GQL Code Builder Refactor to enable Interface/Fragment Type Hierarchy (#485)

* Adding a basic melos config

* Ignoring melos created pubspec overrides

* Adding melos to readme

* pubspec changes

* merge in melos

* added end to end test for failing when on subtypes

* adding reference class

* Fixing Test Setup

* fixes as Conversions

* moving reference files

* reverting state

* Temporarily removing reference serializers

* Adding visual debugging options

* Adding base classes

* Generating the correct classes

* Fixing the G prefix issue with a typemap

* Fixing overrides and implements

* manual file fix

* Revert "Temporarily removing reference serializers"

This reverts commit fbd0b5e.

* Small syntax fixes

* unused import

* Fixes missing G__typename

* fixing nested inline fragments

* clean up some of the documentation

* refactoring data.dart

* Removing FragmentDebugger

* Remove ensureTypenameField

* Removing reference files

* Removes deprecated __typename workarounds

* Fixes duplicate __typenames

* Adding temporary debug statements

* Cleaning up some duplication of __typename

* cleaning up print statements

* removing test asType

* Refactor

* bring back todo comment

* refactoring test

* Adding failing graphql query to generate test where duplicate classes get produced

* Removing fragment debug

* Removing debug tools for PR review

* Fixing diff

* Refactored buildSelectionSetDataClasses

* Split off operations/data.dart

* Refactor inline fragment classes builder

* class utils refactor

* refactor field utils

* Refactor selection utils

* fixing duplication logic

* Adding nested fragments query that used to not generate

* Adding untyped fragments query

* Extended test specs

* Renamed query to match purpose

* adding docsource to builder functions

* Adding Fragment utils

* Inline Fragment Classes refactor

* refactored field utils

* refactored selection builder

* fixing named vs inline fragments type hierarchy

* gql tracer

* Revert "gql tracer"

This reverts commit 735b0fc.

# Conflicts:
#	codegen/gql_debug_tools/bin/gql_code_builder_debug.dart

* breaking off fragment logic inline vs named

* Fixing inline fragment spreads

* Reran codegen with fixes

* importing whole files

Author: caffeineflo