resizable-arraybuffer and growable-sharedarraybuffer should be removed in favor of resizable-buffers

[syg]

I raised an issue some time ago that the resizable-arraybuffer and growable-sharedarraybuffer features should be combined into a single feature. That has resulted in resizable-buffers, but now we just have all 3. :)

Let's remove resizable-arraybuffer and growable-sharedarraybuffer.

[atopal]

cc @Elchi3