remove PyWidget and py-register-widget + refactor PyList as a Python Plugin (#1452)

* remove PyWidget and py-register-widget

* refactor py-list as Plugin

* add newline

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* fix eslint

* handle case if src not supplied

* move inside if

* - Remove src attribute for py-list
- Re-implement as a Python plugin
- Remove pylist.py from examples directory
- Remove PyListPlugin as one of the default ones

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* move PyItem and PyList classes to the plugin

* clean up PyListTemplate and PyItemTemplate from pyscript module

* fix linting

* use PyList instead of PyListTemplate instead

* fix example for todo-pylist

* re-enable and improve test

* move py-list plugin to examples

* fix py-list plugin link

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

pyscriptjs/tests/integration/test_zz_examples.py

@@ -360,15 +360,31 @@ class TestExamples(PyScriptTest):
         self.assert_no_banners()
         self.check_tutor_generated_code(modules_to_check=["./utils.py", "./todo.py"])
 
-    @pytest.mark.xfail(reason="fails after introducing synclink, fix me soon!")
     def test_todo_pylist(self):
-        # XXX improve this test
         self.goto("examples/todo-pylist.html")
         self.wait_for_pyscript()
         assert self.page.title() == "Todo App"
         wait_for_render(self.page, "*", "<input.*?id=['\"]new-task-content['\"].*?>")
+        todo_input = self.page.locator("input")
+        submit_task_button = self.page.locator("button#new-task-btn")
+
+        todo_input.type("Fold laundry")
+        submit_task_button.click()
+
+        first_task = self.page.locator("div#myList-c-0")
+        assert "Fold laundry" in first_task.inner_text()
+
+        task_checkbox = first_task.locator("input")
+        # Confirm that the new task isn't checked
+        assert not task_checkbox.is_checked()
+
+        # Let's mark it as done now
+        task_checkbox.check()
+
+        # Basic check that the task has the line-through class
+        assert "line-through" in first_task.get_attribute("class")
         self.assert_no_banners()
-        self.check_tutor_generated_code(modules_to_check=["utils.py", "pylist.py"])
+        self.check_tutor_generated_code(modules_to_check=["utils.py"])
 
     @pytest.mark.xfail(reason="To be moved to collective and updated, see issue #686")
     def test_toga_freedom(self):