Update interface rules and test

Author: rnkaufman

languages/tree-sitter-stack-graphs-java/src/stack-graphs.tsg

@@ -360,10 +360,11 @@ attribute node_symbol = node            => symbol = (source-text node), source_n
 (interface_declaration
   type_parameters: (type_parameters
     (type_parameter
-      (type_identifier) @type_identifier))) @this {
+      (type_identifier) @type_identifier))
+  body:(_) @body) @this {
   node type_ident
   attr (type_ident) node_definition = @type_identifier
-  edge @this.defs -> type_ident
+  edge @body.lexical_scope -> type_ident
 }
 
 (interface_body) @this {

languages/tree-sitter-stack-graphs-java/test/decl/interface.java

@@ -10,3 +10,7 @@ interface Iterator<E> {
     public E next() {}
     //     ^ defined: 9
 }
+
+interface Set<E> {
+    public Iterator<E> iterator() {}
+}