Fix QuaZip find module on macOS and clean up code. #3088
Type of change
Description and Context
Finding libquazip failed on macOS due to path differences.
This patch also cleans up the find module's code, aligns it with the coding style of the other CMake files and removes clutter that is not needed for KeePassXC such as non-Msys builds on Windows.
CMake found QuaZip on macOS, Windows and Ubuntu.