UTF8 string IDE follow up items

[davidwengier]

Relates to #58848
Proposal - https://github.com/dotnet/csharplang/blob/main/proposals/utf8-string-literals.md

Existing features:

• String split command handler (done in Grab bag of UTF8 string support in IDE features #60599)
• Brace matching for double quotes (done in Grab bag of UTF8 string support in IDE features #60599)
• Structure navigation (done in Grab bag of UTF8 string support in IDE features #60599)
• Pressing F1 on the u8 suffix? (done in Grab bag of UTF8 string support in IDE features #60599)

New potential features:

• Code style option to prefer "abc"u8" instead of new byte[] { 1, 2, 3}` - Code style to convert byte arrays to UTF8 strings #60647
• (The same) code style option to prefer "abc"u8" instead of Encoding.UTF8.GetBytes("literal")
• Code style option to prefer explicit u8 suffix for ROS<byte> x = "ABC" No longer applicable