Compile assets without downtime

We should be able to recompile assets without downtime, that's the only thing that stops us to do regular updates on every platform.

Tasks

• Update shakapaker.yml to add decidim-packs as an env variable
• edit bin/compile-assets to have a different env variable on recompiling
• move freshly compiled assets to decidim-packs and restart (no downtime, just a nginx that will buffer queries waiting for a restart