Fix base58 implementation

[ProkopRandacek]

The base58 implementation seems to be wrong (doesn't agree with online tools) and very over complicated.

The new implementation agrees with two online tools I tried but I'm worried about endianness on other architectures.

I dropped the padding with '1's because the code is always working with 32 byte strings to the number of leading zeroes doesn't need to be stored at all.

[Anton-4]

Can you take a quick look at this @rtfeldman since you wrote the original code? I can do a thorough review after.

[github-actions]

Thank you for your contribution! Sometimes PRs end up staying open for a long time without activity, which can make the list of open PRs get long and time-consuming to review. To keep things manageable for reviewers, this bot automatically closes PRs that haven’t had activity in 60 days. This PR hasn’t had activity in 30 days, so it will be automatically closed if there is no more activity in the next 30 days. Keep in mind that PRs marked Closed are not deleted, so no matter what, the PR will still be right here in the repo. You can always access it and reopen it anytime you like!

[Anton-4]

It may be a while before we get to this @ProkopRandacek because we're focused on the core functionality of the new compiler. We definitely do appreciate your contribution :)

[ProkopRandacek]

all good