This is a high risk change: every byte the card ships is emitted by a
different bundler, minified by a different minifier, and every
stylesheet is compiled by a different sass. The intent is that the
card's behaviour is unchanged.
**Significant development win**: Build time drops from 24s to 1.1s 🎉
Also adds a test suite ('dist') that runs against the built bundle.
Mounts the card from `dist/` the way Home Assistant does, by URL with a
HACS tag, and asserts the entry stays a facade, that no chunk imports
it, that the browser is served the file unmodified, and that the card
starts up and fetches a language chunk lazily.
Runs in Chromium, Firefox and WebKit, so a change of bundler or minifier
is checked against every engine.
Dermot Duffy