Release 2897

• Bump webpack-cli from 4.10.0 to 5.1.4
• Bump database_cleaner from 2.0.1 to 2.0.2
• Bump core-js from 3.29.1 to 3.31.0
• Bump sass from 1.60.0 to 1.63.4
• Bump cucumber-rails from 2.5.1 to 2.6.1
• Bump selenium-webdriver from 4.9.1 to 4.10.0
• Bump css-minimizer-webpack-plugin from 5.0.0 to 5.0.1
• Bump sass-loader from 13.2.2 to 13.3.2
• Bump phonelib from 0.7.6 to 0.8.2
• Bump govuk_design_system_formbuilder from 3.1.2 to 4.0.0

Closed #2896, #2895, #2894, #2893, #2892, #2891, #2890, #2889, #2888, #2879