feat: Replacing static list of NetworkAnnotations with the function

[Gmerold]

Description

This PR is a part of DPDK in UPF.
Context:
NetworkAnnotations needed to support DPDK in the UPF are different from the default ones. This means that the list of NetworkAnnotations will be dynamically generated by the UPF charm, depending on the mode it's running in. This PR implements possibility of passing an arbitrary function generating a list of NetworkAnnotations instead of a fixed list to KubernetesMultusCharmLib's constructor.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have made corresponding changes to the documentation
• I have added tests that validate the behaviour of the software
• I validated that new and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules
• I have bumped the version of the library