implement ANR support
application not responding (ANR) is based on kwin's ability to notice if a GUI bugs out and stops responding. kwin will then offer the user the ability to terminate the process. by expanding this feature a bit using metadata we can thus get fairly reasonable ANR detection.
this is limited to the coredumpd backend because we need some metadata we don't necessarily get from the kcrash backend.
crashedapplication has grown a new wasNotResponding property which indicates the ANR detection. this is false by default but may be switched to true if a kwin ANR marker is found for the crash
if the crash was ANR we'll massage the report data to conform to other platform's ANR reports. this notably includes that sentry reports the crash as "ApplicationNotResponding"