[Bugfix | Anki Mode] 595 - Sync Issues Causing Lost Progress

[tarcisiotm]

Relevant Issue: https://github.com/davidsansome/tsurukame/issues/595

If the user taps the screen too fast after a correct submission, the just submitted correct answer will be marked incorrect, and this apparently gets rejected by Wanikani. I came a across this issue this week after I started using Anki mode, and got more than 200 reviews back when I forced a full sync, after suspecting something was off with Tsurukame's synchronization.

• fixed: Anki Mode tagging correct answers as incorrect when users tapped to show the next review element while the SubjectDetailsView was animating
• added: when users tap the canvas after clicking on a button (correct, incorrect, etc), but before the animation is done, the action gets cached, so the submit button will be automatically be processed once the animation ends

This is my first Pull Request here, so please let me know if something is not following the standards.

[davidsansome]

Cool, thanks for fixing this!