Add option to "clear recent" in folder QComboBox

[rodolakis]

When testing I ended up with a bunch of crap in my recent folder settings. there is no way to clear them besides editing the ini file or opening many good folder to replace them.

This can be useful:
https://www.geeksforgeeks.org/pyqt5-how-to-delete-all-the-items-in-combobox/

I would envision more a "clear recently open" item at the bottom of the combo box like in the picture below, but could also be a push button.