Add support for multiple server credentials in Maven

[reckart]

Description:
Currently, it is possible to generate a settings.xml that contains exactly one server section with GH credentials.
Instead, it should be possible to generate multiple server sections with GH credentials.

Justification:
When a project depends on multiple other projects that each use GitHub packages, then it needs to include a repository declaration for each of these. However, these repository declarations cannot all use the same ID github because the IDs must be unique. So in order to be able to draw in dependencies from multiple GitHub packages repositories, it must be possible to generate multiple server sections, one for each of the GitHub packages repositories.

[marko-zivic-93]

Hello @reckart
Thank you for bringing this up! We will investigate this issue and come back to you as soon as we have some useful information! 😃

[IvanZosimov]

Hi, @reckart 👋 Sorry, but this feature request is a duplicate of #85. I'm going to close your feature request now, meanwhile you can track #85.