- 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.
The arrow is now displayed at the left to be consistent with
other places where folding is used. The arrow icons used are now
consistent with the rest of the editor. The `arrow_up` icon is
no longer used anywhere, so it was removed.
Additional spacing was also added for a better visual appearance.
