Popup Download Manager per Francesco De Stefano

This WebExtension doesn't replace the native browser download manager, but implements it by managing new features with its popup.
=====
Video tutorial: https://youtu.be/gx39ZPrWw8M
=====

This add-on is based on the extension Material Design Download Manager available on github - https://github.com/auxdesigner/Material-Design-Download-Manager

Context menu of the extension popup:
* open the file directly from the popup;
* open the folder where the file was downloaded;
* go to the download page;
* you can copy the original link where you downloaded the file
* you can delete the file you downloaded from the hard disk, directly from the popup;
* remove the downloaded file from the list.
============
Also in the popup is included the button to clean up the entire list of downloaded files and the button to save, in a single file as html format, the history of downloaded documents included in the same list. You can also do an advanced search of the downloaded files using the input at the head of the popup.