Changing path visibilty is slow when a lot of paths change state

[dbrnz]

On AC maps there is a noticeable delay (0.5s) when the visibility state of all neuron paths is changed. This appears to be due to a few things:

1. A single neuron path can consist of more than one line-string features and the visibility state of each feature has to be changed.
2. Path state is maintained both in a MapLibre layer and the DeckGL layer even though only one of these layers is visible. This is so the correct path state is used when layers are switched.
3. MapLibre doesn't have a way of disabling rendering while several features change state to then be redrawn together.
4. This may also be true of DeckGL, although we do have better low level control of its rendering.

[dbrnz]

As an example of 1. above, enabling the bolser_12 nerve centreline (on human male), which has the single bolew-unbranched-12 neuron path associated with it, results in 14 features changing state -- 1 feature is the centreline, 13 are the path:

0 {id: 1167, source: 'vector-tiles', sourceLayer: 'whole-human_pathways', children: Array(0)}
1 {id: 7042, source: 'vector-tiles', sourceLayer: 'neural-routes_pathways', children: Array(0)}
2 {id: 7043, source: 'vector-tiles', sourceLayer: 'neural-routes_pathways', children: Array(0)}
3 {id: 7044, source: 'vector-tiles', sourceLayer: 'neural-routes_pathways', children: Array(0)}
4 {id: 7045, source: 'vector-tiles', sourceLayer: 'neural-routes_pathways', children: Array(0)}
5 {id: 7046, source: 'vector-tiles', sourceLayer: 'neural-routes_pathways', children: Array(0)}
6 {id: 7047, source: 'vector-tiles', sourceLayer: 'neural-routes_pathways', children: Array(0)}
7 {id: 7048, source: 'vector-tiles', sourceLayer: 'neural-routes_pathways', children: Array(0)}
8 {id: 7049, source: 'vector-tiles', sourceLayer: 'neural-routes_pathways', children: Array(0)}
9 {id: 7050, source: 'vector-tiles', sourceLayer: 'neural-routes_pathways', children: Array(0)}
10 {id: 7051, source: 'vector-tiles', sourceLayer: 'neural-routes_pathways', children: Array(0)}
11 {id: 7052, source: 'vector-tiles', sourceLayer: 'neural-routes_pathways', children: Array(0)}
12 {id: 7053, source: 'vector-tiles', sourceLayer: 'neural-routes_pathways', children: Array(0)}
13 {id: 7054, source: 'vector-tiles', sourceLayer: 'neural-routes_pathways', children: Array(0)}
14 features changed enabled state...

[dbrnz]

For the future, maplibre/maplibre-gl-js#4199 should provide a way to control feature visibility (and other styling) without using Map.setFeatureState() and likely be more efficient.