Add names to ast gen.

src/parser/ast.yaml

@@ -1,4 +1,18 @@
 # $schema: ./ast.schema.yaml
+
+# Names
+Identifier:
+  children:
+    - literal:
+        build:
+          type: string
+          from: parse_whole_pair
+FullyQualifiedName:
+  children:
+    - identifiers:
+        rule: Identifier
+        vec: true
+
 # Top-level constructs
 CompilationUnit:
   children: