- Add icons to the up/down bandwidth LineEdits for better
visual grepping.
- Make bandwidth LineEdit texts more prominent when data is being
received/emitted.
- Add more spacing between the up and down bandwidth LineEdits.
- Initialize the bandwidth texts using `set_bandwidth()` to ensure
consistency with the actual bandwidth texts once the profiler
is started.
- Fix icon colors when switching from a dark theme to a light theme
and vice versa.
- Add missing `EDSCALE` constants for hiDPI scaling.