Replace system exit calls with exceptions

[philipp94831]

There are currently 3 system exit calls in the code which should be replaced with exceptions:

• https://github.com/bakdata/kpops/blob/d8e5de23d80356d2348972c21a868ae19d785127/kpops/component_handlers/topic/handler.py
• https://github.com/bakdata/kpops/blob/e198ec710ab3dcd2d1b103fe3a528668c91aaab5/kpops/component_handlers/kafka_connect/kafka_connect_handler.py

[raminqaf]

The exit is replaced. Closing this issue.