Pull sanoid and related files from Github

[furicle]

Would be nice if it would download the required files to install.

suggested here

[furicle]

I suppose we should make it so it will do it using only tools already installed on TrueNAS scale - e.g. curl vs wget vs ? etc
Determining the link to the latest release as well might be a little tricky, since the project releases a tar ball not individual scripts.
Should be doable though.