feat: 132 queuing transfers (#332)

the logic of selecting files has been extended!
From now on selecting file will put the files into a transfer queue, which is shown on the bottom panel.
When a file is selected the file is added to the queue with a destination path, which is the **current other explorer path at the moment of selection.
It is possible to navigate to the transfer queue by using `P` and pressing `ENTER` on a file will remove it from the transfer queue.Other commands will work as well on the transfer queue, like `COPY`, `MOVE`, `DELETE`, `RENAME`.

closes #132

src/ui/activities/filetransfer/components/popups.rs

@@ -670,7 +670,7 @@ impl KeybindingsPopup {
                         ))
                         .add_row()
                         .add_col(TextSpan::new("<P>").bold().fg(key_color))
-                        .add_col(TextSpan::from("               Toggle log panel"))
+                        .add_col(TextSpan::from("               Toggle bottom panel"))
                         .add_row()
                         .add_col(TextSpan::new("<Q|F10>").bold().fg(key_color))
                         .add_col(TextSpan::from("           Quit termscp"))