Add the ability to extract icon on launch

[chrisnharvey]

Automatic icon extraction for AppImage binaries has been removed in the AppImage run time (see AppImage/AppImageKit#346).

Perhaps this is something we can implement here to revive this feature?

[probonopd]

Just use the optional appimaged daemon?

[Yuri6037]

I think this feature should be re-implemented. The appimaged deamon is not able to support every locations. Not everyone uses /home/user/bin for placing AppImages maybe someone will use a different location.
EDIT: Also not everyone would like to register AppImages with the system but instead just wants to place them somewhere then double click on them from file explorer so clearly File Explorers should be able to show icons correctly.