Revert "Restructure to keep __main__ free to be used when using codegen as part"

This reverts commit 87abfe8900.

codegen/__main__.py

@@ -1,6 +1,6 @@
-def main():
+from .codegen import test_str8, test_doubly_linked_list, test_typed_array
-    pass
-
 
 if __name__ == "__main__":
-    main()
+    test_str8()
+    test_typed_array()
+    test_doubly_linked_list()

codegen/dev_main.py

@@ -1,6 +0,0 @@
-from .codegen_example import test_str8, test_doubly_linked_list, test_typed_array
-
-if __name__ == "__main__":
-    test_str8()
-    test_typed_array()
-    test_doubly_linked_list()

run

@@ -1,3 +1,3 @@
 #!/bin/bash
 
-python3 -m codegen.dev_main
+python3 -m codegen