Add option to hide default context state as well, to minimize noise.

We can store these context states in a hash table and display them while users trigger draw-call functions on CanvasDebugger. These are the states that we can process, WebGL: https://www.khronos.org/registry/webgl/specs/1.0/#5.14.3, Canvas2D: http://www.w3.org/TR/2dcontext/#the-canvas-state. Victor, I don't understand what 'hide default context state' means? Does it mean if the state is not changed and is default state. We needn't to show them?

Yes, it'd be nice to only show relevant context info, meaning context state that doesn't have its default values, unless otherwise requested by the user.

I have some ideas to implement this bug. The first one is we could leverage webgl.getParameter() to get the current context state while inspecting it on a method call. We can filter it with default values if we don't want to display them. The second one is storing these context states in a hash table like call-watcher.js and recording every states while they are changed.

Mass-closing inactive (2 years+) bugs on unmaintained devtools components.