Show submap mode on bar

[rReyvn]

Is your feature request related to a problem? Please describe.
I use submap quite a lot, it make me confuse without an indicator that tell me what mode i am in cause sometimes i accidentally activate the submap key and start wondering why my shortcut doesn't works and turn out i forgot to exit the mode

Describe the solution you'd like
The indicator should appear on bar when i press the submap key to enter the mode, the indicator is just a text represent what mode user currently in (hyprland should already have that information i guess) and when i exit the indicator should disappear.