Refactor LnP test framework to parse startup info

[moziliar]

Referencing #11027

In file src/lnp/resources/test.template.properties, test server host is hardcoded. We aim to remove it and use the existing library to get such information, freeing the developer/testers from changing this config unnecessarily.

[anii1827]

Before starting work on this, just need to clarify the requirements as per Reference PR #11027. The properties related to 'test.app.domain=localhost' should be removed, and instead, the code should be modified to parse host information from 'test.app.url=http://localhost:8080' available in test.properties file.

@moziliar is this information above correct?