util: Force text direction of time strings

While the string returned by formatTime() should follow the locale's
text direction as a whole, the actual time part is always expected
to put hours on the left and minutes to the right. It is possible to
enforce that by inserting a left-to-right mark, but so far this is
only done by the Hebrew translation. So in order to not require all
other RTL translations to be fixed individually, just insert the
mark into the returned string ourselves like gnome-desktop's WallClock
code does[0].

[0] https://git.gnome.org/browse/gnome-desktop/tree/libgnome-desktop/gnome-wall-clock.c?h=gnome-3-24#n267

https://bugzilla.gnome.org/show_bug.cgi?id=784130

js/misc/util.js

@@ -280,7 +280,10 @@ function formatTime(time, params) {
             // xgettext:no-c-format
             format = N_("%B %d %Y, %l\u2236%M %p");
     }
-    return date.format(Shell.util_translate_time_string(format));
+
+    let formattedTime = date.format(Shell.util_translate_time_string(format));
+    // prepend LTR-mark to colon/ratio to force a text direction on times
+    return formattedTime.replace(/([:\u2236])/g, '\u200e$1');
 }
 
 function createTimeLabel(date, params) {