Error handling in Stepup-tiqr

[phavekes]

This issue is imported from pivotal - Originaly created at Mar 21, 2022 by Pieter van der Meulen

Check how errors from the tiqr-server-libphp library are handled.

The tiqr-server-libphp library is being refactored. And the way certain functions report errors may change:

• Expect exceptions
• Functions may now return success/failure instead of void
• The return value in case of error may change