Popup auto-anchoring should account for global padding

[andrewharvey]

mapbox-gl-js version: 2.8.2

browser:

Steps to Trigger Behavior

1. Add a popup to the map
2. Set a global padding map.setPadding
3. (for testing) map.showPadding = true
4. Pan the map so the popup intersects the padding

Link to Demonstration

https://codepen.io/andrewharvey/pen/jOZOXGm

Expected Behavior

The auto anchoring of the popup should treat the padding similar to the map edge and re-anchor if it has space.

My reasoning is that global padding is usually set so that content is only shown in the background in that padded area and no focused content should appear there, though it probably does depend on what people are using padding for.

Actual Behavior

The popup will overflow into the global padding and only re-anchor on the map edge.

[andrewharvey]

Potential fix in https://github.com/mapbox/mapbox-gl-js/compare/11841-popup-anchor-padding but need to consider if this should be default (and only) behaviour, opt in, or opt out.