Fix asset size validation

[mbohal]

presently we are using the same numbers for:

• https://webpack.js.org/configuration/performance/#performancemaxassetsize
• https://webpack.js.org/configuration/performance/#performancemaxentrypointsize

I think that makes no sense. The way I see it we only need to worry about maxAssetSize, but maybe I'm wrong. Either way it makes no sense to use the same values for both.