Make query sanitization more extensible

[jturkel]

We (Salsify) are implementing logging of GraphQL queries and variables but our approach is slightly different than the default behavior of GraphQL::Language::SanitizedPrinter:

• We log queries and variables separately to get a more faithful representation of the requests we're getting from clients
• We extended our GraphQL::Schema::Argument subclass to support a redact option rather than just redacting all strings

We were able to implement this by subclassing GraphQL::Language::SanitizedPrinter but it involved some unfortunate copying of code from GraphQL::Language::Printer to restore overridden behavior and copying of code from GraphQL::Language::SanitizedPrinter where we need to inject logic in the middle of a method. Alternatively we could directly subclass GraphQL::Language::Printer but then we would have lost the type bookkeeping from GraphQL::Language::SanitizedPrinter.

This PR proposes a few changes to GraphQL::Language::SanitizedPrinter to make it easier to customize the behavior:

1. Making the inlining of variable values optional with a default that retains the current behavior
2. Adding redact_argument_value? and redacted_argument_value hooks that subclasses can use to more easily customize the redaction behavior

[jturkel]

Rebased to resolve the conflicts with #3171.

[rmosolgo]

Thanks, these changes look great!

[jturkel]

Thanks @rmosolgo. Any plans for a 1.11.5 release soon?

[rmosolgo]

Any plans

I don't usually plan for point releases, but feel free to ask anytime!

🚢 💁‍♂️ https://rubygems.org/gems/graphql/versions/1.11.5

[jturkel]

Woohoo! Thanks @rmosolgo.