schema error.go and typedNode.go should import ld

schema/errors.go

@@ -2,6 +2,8 @@ package schema
 
 import (
 	"fmt"
+
+    ld "gitlab.dms3.io/ld/go-ld-prime"
 )
 
 // TODO: errors in this package remain somewhat slapdash.

schema/typedNode.go

 package schema
 
+import (
+	ld "gitlab.dms3.io/ld/go-ld-prime"
+)
+
 // schema.TypedNode is a superset of the ld.Node interface, and has additional behaviors.
 //
 // A schema.TypedNode can be inspected for its schema.Type and schema.TypeKind,