[Fuzzing] [buyaa-n] Add Base64url encoding/decoding

[MihuBot]

Something went wrong with the Job after 5 minutes 🤷‍♂️

System.Threading.Tasks.TaskCanceledException: A task was canceled.
   at MihuBot.RuntimeUtils.FuzzLibrariesJob.RunJobAsyncCore(CancellationToken jobTimeout) in /home/runner/work/MihuBot/MihuBot/MihuBot/MihuBot/RuntimeUtils/FuzzLibrariesJob.cs:line 33
   at MihuBot.RuntimeUtils.JobBase.RunJobAsync() in /home/runner/work/MihuBot/MihuBot/MihuBot/MihuBot/RuntimeUtils/JobBase.cs:line 171

[MihuBot]

@MihaZupan

[MihaZupan]

#408