Add minimize button to infowindow

[huggla]

I created a minimize button for the infowindow (like I've previously did for the popup #1949).

I'm not sure if or how the tabindex should be changed though.

[johnnyblasta]

You can read about tabindex here but 0 is a good value here. Negative value means the button cannot be focused on.

[tonnyandersson]

Seems to minimize a little too much, resulting in button covering text.

[huggla]

I can't reproduce, but it was probably caused by a mix of px/em/rem in padding/margin. Can you check if I managed to fix it?

[tonnyandersson]

Looks better now. But I noticed something else. If you:

1. Click on an object to open the infowindow
2. Minimize the infowindow
3. Close the infowindow
4. Click on a new object to open the infowindow

...you will notice that the infowindow opens in minimized mode. I don't think this should be the default behavior.

[huggla]

I've fixed so infowindow doesn't remained minimized after clicking close.

[johnnyblasta]

Why is the icon different compared to the popup in #1949