Allow using up to a UTF-32 codepoint as a password asterisk (closes #715)

Signed-off-by: AnErrupTion <anerruption@disroot.org>

res/config.ini

@@ -28,6 +28,8 @@ animation = none
 animation_timeout_sec = 0
 
 # The character used to mask the password
+# You can either type it directly as a UTF-8 character (like *), or use a UTF-32
+# codepoint (for example 0x2022 for a bullet point)
 # If null, the password will be hidden
 # Note: you can use a # by escaping it like so: \#
 asterisk = *