Build toolchain rework

[siarheiyelin]

Prerequisites - part 1.

• Change SCSS imports, so that default export is always used. Reason: to be able to migrate to the recent version
  of style-loader.
• Change the way how "*.doc.ts(x)" modules export things. More specifically: change export = to export default. Reason: to be able to migrate to the most recent version of babel transformer. See "Caveats" section of this article for more details.
• Migrate to newever version of Typescript "4.5.4" -> "4.9.3". Reason: to be able to use most recent Babel transform (see details here).

Prerequisites - part 2. Move sources of each module to the "./src" folder.

Purpose of this change:
-- Simplifies configs
-- fixes issues with rollup watch. It's related to how typescript resolves modules, see more details here. The structure of module would look like this:

<module>/assets/**
<module>/build/**
<module>/src/**
<module>/globals.d.ts
<module>/index.tsx
<module>/package.json
<module>/readme.md

• phase 1. Apply changes to next modules: "uui-core", "uui-components", "uui-timeline", "uui-extra".
  Note: Need to apply changes to next modules as well: "uui", "epam-promo", "loveship". But it's blocked until "feature/uui-themes" branch is merged to develop. Need to wait because of potentially big amount of merge conflicts. This part can be done later.

Migrate "app" module to latest CRA

• Migrate "app" to the latest CRA. Use CRACO to apply any customizations, but try to minimize the customizations as much as possible.
• Add possibility to build "app" using "/build" folder of each dependent module. Note: at current moment it evaluates sources of all modules and builds everything as a single project.

Migrate build of modules to Rollup.

• Migrate to Rollup
• Try this tool to analyze rollup bundle content: https://www.npmjs.com/package/rollup-plugin-visualizer

Future changes

Simplify Webpack/Craco config:

• Migrate to newer version of "react-markdown".
• Move sources of "uui", "epam-promo" and "loveship" modules to the "./src" folder. (phase 2)
• Move "index.tsx" to "./src" folder in each module.

Improve static code analysis:

• Migrate from TSLint to ESLint due to issues in TSLint support of latest typescript. (E.g.: "satisfies" keyword).
• Use Stylelint in webpack dev server. So that we see any issues immediately during development.

Tree shaking:

• Couldn't set "sideEffects: false" to the modules' "package.json" because we still have files like this: uui-core/src/helpers/screenSize.ts

SCSS

• The "~" is deprecated, so we need to remove it (see https://webpack.js.org/loaders/sass-loader/#resolving-import-at-rules). I.e. change this: "@use '~@epam/promo/...'" to this: "@use '@epam/promo/...'". Make sure it works fine in both cases: app build via webpack as well as rollup build. see also: egoist/rollup-plugin-postcss/issues/440

[NatalliaAlieva]

Released in 5.0.0 ver.