Some improvements in the highlighting of literal numbers:
* BUG 386391
Add binaries: `0b1010` [1][3].
* Allow underscores in numbers (Float, Int, Hex, Octal & Binary) [2][3][4].
NOTE: The exact format of the numbers supported can be found in ref. [3] & [4].
* Add hexadecimal floating point: `0xA21.F18p+123` [4].
* Add missing suffixes in numbers: "L" in Hex & Octal, and "D" in Float [3][4].
**References:**
* [1] Java (8) Documentation. Binary Literals: https://docs.oracle.com/javase/8/docs/technotes/guides/language/binary-literals.html
* [2] Java (8) Documentation. Underscores in Numeric Literals: https://docs.oracle.com/javase/8/docs/technotes/guides/language/underscores-literals.html
* [3] Java Language Specification. Chapter 3, Lexical Structure. [3.10.1] Integer Literals: https://docs.oracle.com/javase/specs/jls/se10/html/jls-3.html#jls-3.10.1
* [4] Java Language Specification. Chapter 3, Lexical Structure. [3.10.2] Floating-Point Literals: https://docs.oracle.com/javase/specs/jls/se10/html/jls-3.html#jls-3.10.2