[clang] [clang-format] Add an option to format integer and float literal case (PR #151590)

[Andy MacGregor via cfe-commits]

30Wedge wrote:

> I suggest NumericLiteralCase, Prefix, HexDigit, ExponentLetter, and Suffix for the option names and Leave, Lower, and Upper for the enum values. 

I agree. So much more concise. 

https://github.com/llvm/llvm-project/pull/151590