Improve protocol migration tests on iOS

[hvge]

Currently, the protocol migration tests requires several manual steps. We should investigate whether it's possible to somehow automate this.

The main catch will be to load and unload PowerAuth2.framework dynamically. The alternative is to build a special application that will have several schemes, one scheme per SDK version, so we can simply build & run schemes in right order to test all upgrade steps.

The purpose of this task is to prepare a simple framework for better protocol upgrade testing.