[UI] Make expanding and collapsing goups in Connection List a single left click rather than double click

[lcayrel-oss]

I see you can already expands and collapse group in one click using the down arrow but maybe it would be nice to be able to expand group clicking anywhere on the group button with a single click instead of double click.

You could still right click to open the group menu (Edit group, Delete group) and you can still select multiple groups with shift + left click so I'm not sure making expanding/collapsing in a single click would conflict with other UI actions.

[mfat]

Thanks for your feedback @lcayrel-oss
To me the current behavior seems more intuitive:
select to delete/rename/change color
double-click to expand/collapse