Describe the bug

1. Highlighting is incorrect when inline/block comments and string literals are mixed together.
2. Raw string literals and string literals with prefixes are not supported.

To Reproduce

// /*
/*
// */
"//\"" // ""
R"(//"/*")"
R"(//"/*")"
uR"test(//"R"(/*)"*/")test"
u8"test"
L"test"
U"test"

Screenshots

CP Editor:

VS Code: (mistake due to string literals with different character kinds cannot be concatenated)

Environment

• OS: Manjaro
• Version: 5.9.8

Additional context

We don't need to fix it before 6.0, because CPers seldom write such codes. There are usually not many comments, and string literals are not much more than "Yes"/"No"/"Impossible", etc.

This is a QCodeEditor issue, which is similar to ouuan/QCodeEditor#2, open here for easier bug tracking.