tooling: webpack setup, prod/dev typed configs, remove CRA [week 1]

[sadn1ck]

Changes:

• add webpack 5, webpack dev server and webpack merge
• enabled fully typed webpack configs
• dev and prod webpack configs under webpack/
• proper webpack config loaded in correct env
• add loaders for scss, png, svg and tsx files
  • babel toolchain for js/ts
  • mini-css-extract-plugin, css-loader and sass loader for css
• remove craco, react-scripts
• remove CRA specific path from index.html
• use copy-webpack-plugin to copy from public to build
• ignore copying index.html in public as html-webpack-plugin uses that a template and generates one for us already

Points to note:

• current build output assumes index.html will be in the same folder as other build outputs
  • basically index.html hardcodes relative path to meta icons (favicon, etc) as /icon/filename.png
  • goal is to have it dynamically configurable at build time to allow flexibility in hosting on a static file host or under an actual web server
• all svgs are currently inlined using webpack's loader

Current build is hosted at: https://sadn1ck.github.io/musicblocks-v4/

• Functionality working, but icons are dropped due to public path issues (currently working on that)