Draft: Refresh MTP Storage list

MTP storage needs to be real-time. After storage permission is allowed, the storage list is still empty, causing you to relaunch Dolphin to be able to access devices. What then happens when the authorization is revoked?

I have been having this issue for as long as I can remember. Other users as well: /r/kde/comments/mupl9e/have_to_restart_dolphin_every_time_i_connect_my/ This commit is refreshing device list before querying device list