feat!: esm only build

[AuHau]

This PR implements ESM-only support, this on its own is breaking change, but together with it it brings several other changes:

• the browser bundle is not supposed to be imported like for example await import('https://unpkg.com/@ethersphere/bee-js/dist/index.browser.js')
• the Data interface used to be extended Uint8Array now in order to get Uint8Array you need to use Data.bytes() function

Great write-up about possible issues, how-to guides, motivation etc. done by
Sindre Sorhus: https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c

One issue of migrating to ESM is about imports, which now has to have the full file name including the suffix. A bit non-intuitive thing is that even though we work in the TypeScript realm, the import must have .js suffix. TypeScript can work with it, but unfortunately does not provide a way to transpile .ts suffix to .js or add it based on configuration. There are three ways how to solve this:

• for new projects, just have imports with .js suffix (we should figure out ESLint rule for that)
• for existing Node backend projects that uses something like ts-node then using --experimental-specifier-resolution=node Node flag, lifts this requirement, although it is good to be cautious about this as this is marked as an experimental flag
• for libraries (also can be applied for backends) use the babel-plugin-add-import-extension on top of TypeScript transpiled sources. For example see here