Init world. Basic registry API server

Work in progress .
This commit adds the core registry service implementation with methods to:
- Retrieve all registry entries
- List entries with cursor-based pagination
- Fetch specific server details by ID

go.mod

@@ -0,0 +1,21 @@
+module github.com/modelcontextprotocol/registry
+
+go 1.23.0
+
+require (
+	github.com/google/uuid v1.6.0
+	go.mongodb.org/mongo-driver v1.17.3
+)
+
+require (
+	github.com/golang/snappy v0.0.4 // indirect
+	github.com/klauspost/compress v1.16.7 // indirect
+	github.com/montanaflynn/stats v0.7.1 // indirect
+	github.com/xdg-go/pbkdf2 v1.0.0 // indirect
+	github.com/xdg-go/scram v1.1.2 // indirect
+	github.com/xdg-go/stringprep v1.0.4 // indirect
+	github.com/youmark/pkcs8 v0.0.0-20240726163527-a2c0da244d78 // indirect
+	golang.org/x/crypto v0.37.0 // indirect
+	golang.org/x/sync v0.13.0 // indirect
+	golang.org/x/text v0.24.0 // indirect
+)