When you press `V` to go into visual-line mode in Vim,
`selections.line_mode` is true and the selection contains _lines_.

But `$ZED_SELECTED_TEXT` always contained just the cursor location or
any non-line-mode selection that was previously made.

Release Notes:

- Fixed `$ZED_SELECTED_TEXT` variable in Tasks ignoring whether
visual-line-mode in Vim was used.