Improve RAML endpoint extraction

[hahwul]

Summary

• support RAML resourceTypes, traits, queryString, schemas, trace, and multiple mediaType forms
• resolve RAML includes with source directories so nested relative includes work
• add advanced RAML functional fixture covering uppercase methods and nested includes

Tests

• crystal spec spec/functional_test/testers/specification/raml_spec.cr --error-trace
• just test
• just build
• just check
• ./bin/noir -b spec/functional_test/fixtures/specification/raml_advanced -f json