Option to rename on "create new file/folder" if name already exists

Submitted by FateRover

Assigned to Xfce Bug Triage

Link to original bug (#14706)

Description

thunar will always name the newly created folder "new folder",if a new folder has been exist in the directory, we should type another name like "new folder 1",plz make thunar detect the folder or file names which are existed,and generate the default name by "new folder 1" "new folder 2" "new document 1"...etc.