Add possibility to tap into PowerAuthLog

[kober32]

Scenario why we need this:

• Client distributes a test build to testers
• Testers see some issues with the app and need to provide logs
• The app gathers logs and offers the possibility to send them via email
• PowerAuth only enables logging into the console via the standard android.util.Log facility, which is not usable for this scenario
• Also, the client can gather errors and warnings in production as PowerAuthLog reports these errors via this class as well.

Solution:

Add a listener to the PowerAuthLog to be able to process logs by the integrator