fix max height of opened filter pane to just over the bottom menu icons

[wbazant]

#416 proposes:

• Make the filter pane fullscreen (extend to footer)

I tried it, and it seemed a bit wasteful when the map is zoomed in and just a few locations are available. The proposed resolution is to flex the tree select, and let it be as big as it wants to be, with some bounds.

fa96e6b adds 5vh as the minimum (a tiny bit of white space so the user knows the feature is still there) and 65vh as max ( a tiny bit of map still visible so the user knows tha map is still there).

[wbazant]

This is live and working as the issue intended, @ezwelty I'll leave you to either close or suggest improvements to this one

[ezwelty]

@wbazant The fixed maximum height leads to varying results on different screen sizes: either too short (the filter could use more space but can't), just right, or too long (the filter awkwardly covers part of the lower navigation, or worse, extends beyond the bottom of the screen such that you end up with double scroll of the container and the type tree within).

I get your point about letting it be shorter if the type filter is small – to leave some of the underlying map visible – but I think the maximum height should be set so that it extends either to the bottom of the map (to leave the bottom navigation perfectly exposed) or to the bottom of the screen.

Trying to make out of the HTML/CSS layout in React leaves me dizzy, so I mocked up a demo here (with filters extending to bottom of map):
https://jsfiddle.net/oyndt8q4/

[wbazant]

For clarity, the UI sometimes does e.g.

and the proposed resolution is to let it extend to at most just under the menu (or to the bottom of the screen if that ends up looking better).