Migrate from Sprache to Superpower

[rogusdev]

https://github.com/datalust/superpower is apparently the replacement for sprache, by sprache's author, per sprache/Sprache#194 (comment) .

Hopefully switching to that would be easy, and also allow us to remove the extra deps that are only necessary to avoid snyk/checkmarx warnings per #68 .

[Philipp-Binder]

In #106 I started from your first commit regarding superpower and worked on just exactly replacing Sprache as good as possible.

I think there is much space for Improvements by using the new concept of TokenParsers.
But that would be a huge make-over which also requires deep changes in the testing-project I guess.

If this direction is of interest to you, I'd dive into it after the replacement ist done.

[rogusdev]

I am definitely open to using the newer superpower library more thoroughly. I am not in a rush to do anything more than make the migration myself, but I heartily support you reviewing things and making changes if it excites you :)

[rogusdev]

Resolved by #106