[Feature Request] Add draw parsing

[moi15moi]

Currently, we ask the user to use pyonfx to parse the drawing:

ass_tag_analyzer/ass_tag_analyzer/ass_item/ass_valid_tag/ass_valid_tag_clip.py

Lines 18 to 21 in e8854e5

	"""
	If you wanna parse an Vector Clip, see the PyonFX library.
	Especially the Shape module: https://pyonfx.readthedocs.io/en/latest/reference/shape.html
	"""

ass_tag_analyzer should parse the draw by itself.
Here is the detail of VSFilter and libass implementation

VSFilter Implementation

1. https://sourceforge.net/p/guliverkli2/code/HEAD/tree/src/subtitles/RTS.cpp#l1372
2. https://sourceforge.net/p/guliverkli2/code/HEAD/tree/src/subtitles/RTS.cpp#l299
3. https://sourceforge.net/p/guliverkli2/code/HEAD/tree/src/subtitles/RTS.cpp#l341

Libass Implementation

• https://github.com/libass/libass/blob/master/libass/ass_drawing.c
• https://github.com/libass/libass/blob/master/libass/ass_drawing.h
• https://github.com/libass/libass/blob/master/libass/ass_outline.c
• https://github.com/libass/libass/blob/master/libass/ass_outline.h