Ability to save drawings

- Added `toolbox` to the common methods.
- `toolbox.save_drawings_under` can save drawings under a specific `topbar` widget. eg `chart.toolbox.save_drawings_under(chart.topbar[’symbol’]`)
- `toolbox.load_drawings` will load and display drawings stored under the tag/string given.
- `toolbox.export_drawings` will export all currently saved drawings to the given file path.
- `toolbox.import_drawings` will import the drawings stored at the given file path.

Fixes/Enhancements:
- `update` methods are no longer case sensitive.
- HorizontalLines no longer throw cyclic structure errors in the web console.
- `API` methods can now be normal methods or coroutines.

setup.py

@@ -5,7 +5,7 @@ with open('README.md', 'r', encoding='utf-8') as f:
 
 setup(
     name='lightweight_charts',
-    version='1.0.14.1',
+    version='1.0.14.2',
     packages=find_packages(),
     python_requires='>=3.8',
     install_requires=[