Schema Coordinates (#3044)
Depends on #3115
Implements https://github.com/graphql/graphql-spec/pull/794/
Adds:
* DOT punctuator in lexer
* Improvements to lexer errors around misuse of `.`
* Minor improvement to parser core which simplified this addition
* `SchemaCoordinate` node and `isSchemaCoodinate()` predicate
* Support in `print()` and `visit()`
* Added function `parseSchemaCoordinate()` since it is a parser entry
point.
* Added function `resolveSchemaCoordinate()` and
`resolveASTSchemeCoordinate()` which implement the semantics (name
mirrored from `buildASTSchema`) as well as the return type
`GraphQLSchemaElement`
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Co-authored-by: Benjie Gillam <benjie@jemjie.com>
Co-authored-by: Mark Larah <mark@larah.me>
Co-authored-by: Yaacov Rydzinski <yaacovCR@gmail.com>
