Fix Cursor{Up,Down} after DeleteLine and CutLine

After executing CutLine or DeleteLine action, the cursor is at the
beginning of a line (as expected) but then moving the cursor up or down
moves it to an unexpected location in the middle of the next or previous
line. Fix this by updating the cursor's LastVisualX.

internal/action/actions.go

@@ -1211,6 +1211,7 @@ func (h *BufPane) CutLine() bool {
 	h.lastCutTime = time.Now()
 	h.Cursor.DeleteSelection()
 	h.Cursor.ResetSelection()
+	h.Cursor.StoreVisualX()
 	InfoBar.Message("Cut line")
 	h.Relocate()
 	return true
@@ -1256,6 +1257,7 @@ func (h *BufPane) DeleteLine() bool {
 	}
 	h.Cursor.DeleteSelection()
 	h.Cursor.ResetSelection()
+	h.Cursor.StoreVisualX()
 	InfoBar.Message("Deleted line")
 	h.Relocate()
 	return true