Add message box when trying to move out of bounds

[my-tien]

When the user tries to jump to a location outside the boundaries, this is currently only visible in debug output. Add a message box.

[Optiligence]

for jump it’s reasonable, but moving at the edge becomes really annoying then
not sure if distinguishing them is that beneficial
so i would vote for statusbar content instead

[my-tien]

Update: put the warning into the snack bar