Add WebGL1 Canvas Context

[petele]

Replaces #1515

[captainbrosset]

I'm a bit unsure about the level of granularity here, and this is probably due to the fact that I don't know WebGL well enough. @petele @ddbeck @foolip what are your thoughts on the proposed features here?

For example, does "WebGL 32-bit floating-point color buffers" need to be its own feature? How about "Color management for WebGL"?

Are these sufficiently distinct from using WebGL? Do they allow developers to achieve a specific task? Or are they just part of how you use WebGL?

The concern I have with this is going too granular and departing from the notion of "features" which we want to be more relatable to developers than what BCD provides.

[petele]

@foolip, @ddbeck, and I have been going back and forth on these a whole bunch and have already merged a number of items into the main 'feature'. I get the concern about too many features, but the remaining features are each something that allows a specific functionality beyond the scope of general WebGL.

[captainbrosset]

Ok. Then I guess that's fine.

[ddbeck]

This should be renamed to desynchronized-canvas-webgl.yml.