Credits don't work when updates are suspended

[kring]

Most of the cesium-native integrations have a "Suspend Update" feature. When enabled, they don't call Tileset::updateView, so the current set of loaded and selected tiles is frozen in place. This is useful for debugging.

But this doesn't work well with credits. If updateView isn't called in a frame, then none of that tileset's credits will be shown in that frame. The credits disappear, rather than being frozen like the tiles are.

One way to solve this is to move the "suspend update" feature into cesium-native, probably in TilesetOptions. Then the integrations would always call updateView, but when updates are suspended it would exit early without loading or selecting tiles. It would apply the previously-selected credits to the current frame, though, fixing this bug.

[lilleyse]

I ran into this issue in Cesium for Omniverse yesterday as well.

[j9liu]

This seems to have been indirectly solved by #1125 and the credit system rework.