Add tests for NetworkButton component

[davidlag0]

Pull Request type

Please check the type of change your PR introduces:

• [ ] Bugfix
• [ ] Feature
• [ ] Code style update (formatting, renaming)
• [ ] Refactoring (no functional changes, no API changes)
• [ ] Build-related changes
• [ ] Documentation content changes
• [x] Other (please describe):

This is another PR to keep adding tests to the codebase, for the frontend specifically.

What is the current behavior?

Codebase has no tests. This is meant to improve the situation and ease future code changes.

Issue Number: #135

What is the new behavior?

• Tests were added for NetworkButton component
• Because NetworkButton uses code from utils/IP, tests were also added to fully cover these utils to keep the code coverage at 100% for code currently covered by tests.

Does this introduce a breaking change?

• [ ] Yes
• [x] No

Other information

[davidlag0]

When adding tests for utils/IP I recalled there is a PR to add IPv6 support. I have noticed that several functions in utils/IP would need to be updated. I have not checked if code has to be updated elsewhere as well for IPv6 support. At least the file is covered with tests now including tests that show IPv6 is not supported with some functions, which should help to make changes to support IPv6!

[dec0dOS]

@davidlag0, thanks a lot for your work! Seems to be everything is fine, ready to merge now.