Currently, the GraphQL schema is exposed under /graphql/schema (so
relative to the main graphql endpoint) and is configurable with the
`spring.graphql.schema.printer.path` configuration property.
We think we should make the schema location more consistent to help
tools and various Gateway products. Also, we don't see right now a
strong use case for such a configuration property.
This commit removes the configuration property and sets the schema
location under `/graphql/schema`(`/graphql` being the main graphql path
configured by the application).
Closes gh-79