refactor(clew): rename AST extractor script

src/clew/BUILD.bazel

@@ -5,12 +5,12 @@ py_binary(
     srcs = ["clew.py"],
     main = "clew.py",
     deps = [
-        ":dump_ast",
+        ":extract_renpy_ast",
         "//third_party/python:rpycdec",
     ],
 )
 
 py_library(
-    name = "dump_ast",
-    srcs = ["dump_ast.py"],
+    name = "extract_renpy_ast",
+    srcs = ["extract_renpy_ast.py"],
 )