feat: converter accepts the constructs of goodluke and SaintlyCorruption

`init -490 screen`, `import x as y` and `from m import A as B`, classes with @renpy.pure, pickle hooks
on classes, `*` items in tuples and lists, generator functions (yield statements; the player runs them
to the end), multi-line expressions that need brackets, Null() and Animation() images, images given as
expressions (`"path/{}.png".format(x)`, f-strings), window statements in init, `offset` in ATL, input
widgets with their values and the focus/confirm actions, `continue` and `break` in screens, `drag`
and DiamondBox-style `fixed` with cell_size, `getattr(...)()` calls, transforms called with arguments,
and the whitelist for the new runtime. JSON files of a game are shipped as data files. Also fixes
blocking_names failing on a call of a call during full conversion.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

backend/tests/test_converter.py

@@ -57,10 +57,10 @@ def test_if_chain_and_menu():
 
 
 def test_unsupported_python_is_reported_not_fatal():
-    d = parse("init python:\n    def f():\n        yield 1\n    x = 1\nlabel start:\n    $ y = x\n")
+    d = parse("init python:\n    def f():\n        received = yield 1\n    x = 1\nlabel start:\n    $ y = x\n")
     assert d.init_code[0]["op"] == "set" and "f" in d.deferred  # reported once something calls it
     from app.converter.compatibility import audit_ir
-    d = parse("init python:\n    def f():\n        yield 1\nlabel start:\n    $ f()\n")
+    d = parse("init python:\n    def f():\n        received = yield 1\nlabel start:\n    $ f()\n")
     audit_ir(d)
     assert d.blockers