Avoid redundant uniform setup

[lucaswoj]

ref #2629 (comment)

Frame duration has increased due to data-driven styling architectural changes which require redundant uniform setup. We should consider ways to mitigate this problem.

I am very interested in building a prototype that leverages mikolalysenko/regl to avoid redudant WebGL state setup and make our code more robust.

cc @mourner @ansis

[lucaswoj]

Other options:

1. build our own efficient declarative uniform binding system (effectively a subset of regl)
2. enforce consistent uniform state across rendered tiles

[lucaswoj]

Closing in favor of #145