Add support for WebGL2 `MAX_COLOR_ATTACHMENTS` and `MAX_DRAW_BUFFERS`
Adds support for using the WebGL2 enums `MAX_COLOR_ATTACHMENTS` and `MAX_DRAW_BUFFERS` with `GetParameter`. See https://www.khronos.org/registry/webgl/specs/latest/2.0/#3.7.2
Add support for WebGL2 `MAX_COLOR_ATTACHMENTS` and `MAX_DRAW_BUFFERS`
Adds support for using the WebGL2 enums `MAX_COLOR_ATTACHMENTS` and `MAX_DRAW_BUFFERS` with `GetParameter`. See https://www.khronos.org/registry/webgl/specs/latest/2.0/#3.7.2
