Allow to measure critical performance aspects with the qmlprofiler

When using a type autogenerated by ifcodegen, the QML type might be used in a performance critical section of the UI e.g. during startup.
To identify the aspects slowing a system down the qmlprofiler is used.

This task is about adding the performance measurement code to the interfaceframework, and potentially to the autogenerated code (if that makes sense). It should allow the user to see the following things:

• How long does it take to load a backend plugin
• How long does it take to instantiate the plugin class
• How long does it take to intialize a backend