Investigate how to provide a dSYM package for iOS builds

[herzbube]

The current state for iOS builds is to provide a static library/framework that can be embedded by the consuming application into its executable. The consuming application build will then produce a dSYM package which allows to symbolicate a crash report as far as

1. Decoding the call stack at the crash site
2. And decoding the involved method names

But so far it has not been possible to show the source code of the library (e.g. libsgfc++) that caused the crash, nor any parameter or local variable values.

The goal of the investigation is to find out at minimum how to link to the library source code so that Xcode shows the exact line of code that caused the crash.