QoL - Allow hiding the levelup reminder icons

[eleriaqueen]

These icons are good for new players but an annoyance for returning or veteran players.

[nmeylan]

Can this be related to #78? not showing if skilltree or status window is already opened would work?
But i can add an option anyway

[eleriaqueen]

It would be perfect if we could hide them completely with an option, I think.