Replacing ASCII with just UTF8 as the new and only 'String'?

[PaulFidika]

I've been thinking about this: Move core has two 'string' libraries; ascii and utf8. Most developers will find this somewhat confusing at first. In order to reduce complexity for devs first joining, I might simply remove all support and reference to ascii, and simply refer to utf8 as 'string'. This would simplify things a bit.

The only issue with this I can think of is that some devs might want their strings to be an ascii-only subset of utf8 strings, and they might want to enforce this at the byte-level, rather than doing their own custom application-level input validation.

Thoughts?