build: Optimize Docker image with bundled server and Alpine

[fboucher]

This fix #34

Using a multi-phase build we can reduce a lot the size of the final image.

Metric	Original Dockerfile	Optimized Dockerfile	Reduction
Compressed Size (Layer Download)	159 MB	43.9 MB	-72.4%
Uncompressed Size (Disk Usage)	700 MB	151 MB	-78.4%
Node Modules Size	~200+ MB	0 Bytes	-100%
Security Attack Surface	Large (contains Debian utilities and unused dependencies)	Extremely Low	Fewer OS packages and packages in runtime