feat(sdlmerge): add shared types for GraphQL schema handling

Introduce types for managing fielded, enum, union, and scalar shared types.
Implement functionality for comparing values and creating field sets.
Enhance schema extensions by integrating new visitors for enum types.

go.mod

@@ -17,7 +17,7 @@ require (
 	github.com/sparetimecoders/goamqp v0.3.1
 	github.com/stretchr/testify v1.10.0
 	github.com/vektah/gqlparser/v2 v2.5.23
-	github.com/wundergraph/graphql-go-tools v1.67.4
+	github.com/wundergraph/graphql-go-tools/v2 v2.0.0-rc.160
 	gitlab.com/unboundsoftware/eventsourced/amqp v1.8.0
 	gitlab.com/unboundsoftware/eventsourced/eventsourced v1.17.0
 	gitlab.com/unboundsoftware/eventsourced/pg v1.16.0
@@ -33,13 +33,11 @@ require (
 	github.com/google/uuid v1.6.0 // indirect
 	github.com/gorilla/websocket v1.5.1 // indirect
 	github.com/hashicorp/golang-lru/v2 v2.0.7 // indirect
-	github.com/jensneuse/byte-template v0.0.0-20200214152254-4f3cf06e5c68 // indirect
 	github.com/lib/pq v1.10.9 // indirect
 	github.com/mfridman/interpolate v0.0.2 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/rabbitmq/amqp091-go v1.10.0 // indirect
 	github.com/russross/blackfriday/v2 v2.1.0 // indirect
-	github.com/santhosh-tekuri/jsonschema/v5 v5.3.1 // indirect
 	github.com/sethvargo/go-retry v0.3.0 // indirect
 	github.com/sosodev/duration v1.3.1 // indirect
 	github.com/tidwall/gjson v1.17.0 // indirect
@@ -47,6 +45,7 @@ require (
 	github.com/tidwall/pretty v1.2.1 // indirect
 	github.com/tidwall/sjson v1.2.5 // indirect
 	github.com/urfave/cli/v2 v2.27.5 // indirect
+	github.com/wundergraph/astjson v0.0.0-20250106123708-be463c97e083 // indirect
 	github.com/xrash/smetrics v0.0.0-20240521201337-686a1a2994c1 // indirect
 	go.uber.org/multierr v1.11.0 // indirect
 	golang.org/x/mod v0.23.0 // indirect