[FIX][IMP][web_decimal_numpad_dot] Support float time

- All Char widgets were getting affected by this behavior.
- Time float widgets now get ":" instead of "," or ".".
- Little code refactor.
- Only detect numpad dot, not normal dot and comma.

web_decimal_numpad_dot/README.rst

@@ -40,6 +40,7 @@ Contributors
 * Oliver Dony <@odony>
 * Wim Audenaert <Wim.Audenaert@ucamco.com>
 * David Vidal <david.vidal@tecnativa.com>
+* Jairo Llopis <jairo.llopis@tecnativa.com>
 
 Maintainer
 ----------