It is possible in latest versions of catfish to drag and drop from a search box. It copy the files. You have to delete them after in catfish. I try to move the files with no success. When you have several files with the same name, it will ask you what to do if you copy them in one directory.
I try it with version 4.16.0 and it works. I tested with an older version of catfish (1.4.4) and it doesn't work.
I think it's from version of Catfish 1.4.7. Source : omgubuntu.co.uk.
Elsewhere, Catfish now lets you drag search results out of the app
and on to other applications. When dragging file(s) to a file manager
(e.g., Nautilus, Nemo, Caja, et al) the file(s) will usually be
copied, while dragging files onto an application (e.g., GIMP, Pinta,
LibreOffice, etc) will open the file inside the application.
You can either install a new Ubuntu version (and reinstall catfish) or catfish version 4.16 under Ubuntu 18.04.
To uninstall an old catfish version before installing the new one :
sudo apt-get remove catfish
If you want to remove all configuration files and data (including your index) ;
Note : In case the following installation instructions doesn't work for you, you will have to reinstall the old catfish version and reindex.
sudo apt-get purge catfish
Install the version 4.16 of catfish under Ubuntu 18.04 (tested with Xubuntu 18.04 - xfce and Ubuntu Gnome 18.04)
sudo apt-get update
sudo apt-add-repository universe
# The gdebi utility automatically pulls in required dependencies (sometimes...).
sudo apt-get install gdebi-core
# Or Downloads folder in your locale.
cd ~/Downloads
wget http://http.us.debian.org/debian/pool/main/x/xfconf/libxfconf-0-3_4.16.0-2_amd64.deb
wget http://http.us.debian.org/debian/pool/main/x/xfconf/gir1.2-xfconf-0_4.16.0-2_amd64.deb
wget http://http.us.debian.org/debian/pool/main/c/catfish/catfish_4.16.0-1_all.deb
sudo apt install ./libxfconf-0-3_4.16.0-2_amd64.deb ./gir1.2-xfconf-0_4.16.0-2_amd64.deb
sudo gdebi catfish_4.16.0-1_all.deb
