Support Guild Operators based installs

[wolf31o2]

Let's detect this common configuration method for a Cardano node and act accordingly.

[wolf31o2]

These installs use CNODE_HOME for locating themselves, and the default is /opt/cardano/cnode

[rdlrt]

Couple of minor notes:

• While CNODE_HOME is referred to internally for scripts, it does not require to be present at session level (it defaults to using parent of current folder). The folder structure might be more relevant there as populating variables for environment are done via env file (User variables section) which sets defaults based on above folder structure.
• Some features like detecting op-cert is captured from node's invocation comand, unless overwritten by operator by specifying alternate location.

Feel free to yell out if there are changes / suggestions or queries to improve either of the tooling =]

[wolf31o2]

I've looked at this several times and keep running into a major issue with env not being an environment file, rather a full-blown shell script. It's a major lift to try to properly detect this installation type. It gets even more difficult with containers, as I need a matching file-system, not just PID namespace.

I would definitely accept contributions on this, even if it came in pieces. I'm going to mark it as help wanted and back burner it.