drop-target: End dropped path lists with a space

Currently dropping multiple files into Console will result in quoted paths each separated by a space ('/a' '/b' '/c'). As it doesn't end with a space, if a second set is dropped some paths will not be separated by spaces ('/a' '/b' '/c''/d' '/e').

This MR adds a space to the end of dropped lists. This allows a list of files to be created over several drops.

before	after
Screencast_from_2023-08-30_15-08-14	Screencast_from_2023-08-30_15-12-49