utils,playertoolbar: Use regular colon as time divider
The GNOME HIG suggests using an alternate character for the hour, minutes divider (Teams/Design/hig-www#127). This leads to reversed time ordering in RTL languages.
Use „:” (U+003A) again instead of „∶” (U+2236) for now. This will fix the reversed time in RTL languages.
Fixes: #509 (closed)