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.

.github/FUNDING.yml

@@ -1,4 +1,2 @@
-# These are supported funding model platforms
-
 github: louisnw01
-custom: https://www.buymeacoffee.com/7wzcr2p9vxM
+custom: https://www.buymeacoffee.com/7wzcr2p9vxM/