Runtime mode

## Describe the enhancement

I would like Linaria to have a "runtime" mode with client-side style compilation like `styled-components` has. This enables working with [esbuild](https://github.com/evanw/esbuild) and [swc](https://github.com/swc-project/swc) bundlers for development.

## Motivation

`esbuild` and `swc` are much faster and zero-dependency, so I don't need to have multi-gigabyte `node_modules` with `webpack` and `babel`. I still want to use them for release builds (to precompile and split `css` files), but I have a separate CI pipeline for that.

## Possible implementations

Linaria could have a top-level export like `linaria/runtime` which I can use as alias to `linaria` for development builds