Add possibility register reportportal listener dynamically as library

[petr-kus]

Is your feature request related to a problem? Please describe.
Currently, the listener can only be instantiated during execution. However, there are situations where dynamically loading it as a library is useful. This is especially true when you lack control over the command line (such as in CI/CD setups managed by other teams or systems with hardcoded configurations beyond your control).

Describe the solution you'd like
I would like to be able to dynamically import ReportPortal as a library and thereby start or initialize a listener

Additional context
The register listener as library is described in this article from robot framework documentation.

The screenshot from the code of reportportal listener and compared with docu...