Refactor block animations to not store data on SVG elements #6595
Description
Describe the bug
Currently the block animations code stores data on properties of SVG element objects, which are also referenced in the main block code. This design has caused us problems in the past (namely #6541) because it is difficult to refactor the code when you're dealing with side effects on "private" properties that are triggered by other files.
Suggested solution
I think the easiest thing is just to add some public getters and setters for handling the skew and the translation (so that the block code and the block animation code can both mess with it). But there may also be a more elegant solution that does better at information hiding.
Additional Info
Related to #6559