Bump optimize-css-assets-webpack-plugin from 2.0.0 to 4.0.0 in /client#16

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dependabot/npm_and_yarn/client/optimize-css-assets-webpack-plugin-4.0.0Arne117/MEVN-Stack-Boilerplate:dependabot/npm_and_yarn/client/optimize-css-assets-webpack-plugin-4.0.0Copy head branch name to clipboard