Add option to auto_zoom_on_focus panes in rows or columns independently

[simeonrediger]

I often use 2 columns with the right column split into 2 rows and auto_zoom_on_focus set to [0.5, 0.9]. This allows me to see 2 files side by side, with 2 groups of files to choose from on the right. While I can view the left pane regardless of which pane I am focused on in the right column, I can only see the top pane in the right column when focusing the left pane (presumably because the left pane and the top pane are both in the first "row").

It would be useful if I had the option to simultaneously view the left pane and the top or bottom pane in the right column. It doesn't seem like it would generally be useful for auto_zoom_on_focus to focus a whole row or column of panes together.

Edit: It looks like it is technically possible to view the left pane and the bottom-right simultaneously, but I have only accomplished this by manually dragging the bottom-right pane's border to fill the right column. If I then click the left pane, the bottom-right pane, and then the left pane, it focuses the top-right pane again.