[Enhancement] Support for continuations/pagination when calling get_library_playlists() method

**Is your feature request related to the youtui app, or one of the helper crates (e.g ytmapi_rs)?** Please list either youtui or the crate the feature request relates to. ytmapi_rs **Is your feature request related to a problem? Please describe.** A clear and concise description of what the problem is. Ex. I'm always frustrated when [...] Calling `get_library_playlists()` returns just 25 playlists, although I have 1000+ already created. **Describe the solution you'd like** A clear and concise description of what you want to happen. Ideally, I would need the `get_library_playlists()` method to return ALL existing playlists. If that is not possible, I would like to know how to use continuations in the calling code so that I end up getting all those playlists. **Describe alternatives you've considered** A clear and concise description of any alternative solutions or features you've considered. None so far. **Additional context** Add any other context or screenshots about the feature request here.