the main widget before presented a layout to hold the indicator,
however, for the causual case, this is not really needed. The indicator
itself is anyways going to be a more general prupose widget soon, where
the layout here can be taken as an starting point.
Additionally, this fixes general displaying of the indicator, before the
box padding refactor, a padding would have changed the minsize of the
mix, this is not the case anymore, which forces us to calculate the
minsize of the indicator theme.
Depends on D10763