Make the container built smaller

Currently the container clocks at almost 4GB.

```
$ docker image ls
REPOSITORY                 TAG       IMAGE ID       CREATED        SIZE
ghcr.io/cci-moc/lsvd-rbd   main      09ca3c6519dd   12 days ago    3.82GB
```

Using multi stage builds, it is possible remove intermediary artifacts and compile-only dependencies from the final built image, significantly reducing the size. 