Update juvix-stdlib to remove non-ASCII indentifiers

[paulcadman]

This PR updates the juvix-stdlib to the current main commit which includes:

• https://github.com/anoma/juvix-stdlib/issues/59
• https://github.com/anoma/juvix-stdlib/issues/101

All the Juvix test suite files and examples in this repo have been updated to be compatible with the new stdlib.