PICARD-2186: Fix detection of running app in Windows (un)installer

[phw]

Summary

• This is a…
  • Bug fix
  • Feature addition
  • Refactoring
  • Minor / simple change (like a typo)
  • Other
• Describe this change in 1-2 sentences:

Problem

• JIRA ticket (optional): PICARD-2186

The Windows installer attempts to detect the Picard Window to stop installation / uninstallation while Picard is running. This detection was broken since Qt at some point changed from a static window class name of "Qt5QWindowIcon" to a version specific one like "Qt512QWindowIcon".

Solution

The Qt window class name changed from a generic one to a version specific one. Use a function to search for partial matches.

Compare:

https://nsis.sourceforge.io/Enhanced_FindWindow_for_variable_window_title_names

https://nsis.sourceforge.io/Check_whether_your_application_is_running#Using_a_window_class_or_title

[rdswift]

I'm not an expert with NSIS installer because I use InnoScript for all my Windows application installations, but from my limited understanding this looks good to me.

[phw]

Thanks for checking. I tested it on two systems and it worked. This method is not 100% fool proof, but when it was still working (in older Picard versions of the 1.x era) it was doing its job :)