improve numeric literal regexes

[morganholly]

• custom literal no longer matches standard suffixes
• decimal float now matches with decimal point and/or e
• previous decimal int regex was named binary, that is fixed
• decimal int now matches with suffixes
• all literals include unary minus
• a couple commits include regex101 demos to show matching and nonmatching inputs, they have been visually confirmed in vscode

[saem]

Thanks