Implement visual regression testing solution

[amypellegrini]

Investigate between the following options and implement the most suitable solution:

• https://github.com/garris/BackstopJS
• https://github.com/oblador/loki
• https://github.com/mjhea0/cypress-visual-regression
• https://github.com/americanexpress/jest-image-snapshot

The plan is:

1. Migrate all the sheet music rendering components out of closed source repo as they are now, without any changes.
2. Add visual regression testing to all of them to enable safe refactoring
3. Implement any enhancements while maintaining visual regression testing (backwards compatibility)