HexFormat/NumberHexFormat has a `prefix` String fi...

# stdlib

[MiguelDecimal128]

HexFormat/NumberHexFormat has a prefix String field which defaults to "0x".
Users who are working at the UTF-8 level are forced to call prefix.encodeToByteArray() repeatedly.
The immutable NumberHexFormat should include prefixUtf8 and suffixUtf8 to reduce heap churn and for ease of use.
What is the process for me to request this?

[spand]

Pretty sure everything goes to kotl.in/issue