Correctly handle stopPropagation for iphone and ipad devices

[oguzeroglu]

Fixes touch bugs that occur frequently in Sentry (https://sentry.io/organizations/camunda-modeling/issues/1640119817/?project=5218065&query=is%3Aunresolved&statsPeriod=24h)

For the solution, see: https://stackoverflow.com/questions/26027362/how-to-stoppropagation-w-hammer-js-2-0

I tested this with my iPhone and can confirm it works. One can also test this with XCode iPhone simulator & remote debugging via Safari on MacOS devices.

Definition of Done

• corresponds to the design principles
• corresponds to the code standards
• passes Continuous Integration checks
• available as feature branch on GitHub
  • contains the cleaned up commit history
  • commit messages satisfy our commit message guidelines
  • a single commit closes the issue via Closes #issuenr

[barmac]

It works correctly on iPhone simulator.

[nikku]

Let us merge and ship it then and see if it fixes things in real life, too.