Custom metrics

[Deezzir]

• Compiled a list of metrics that might be useful in production (can be extended anytime).
• Added a fallback to use the custom list to the dcgm-exporter app.

[samuelallan72]

Thanks, this looks good. The file structure is nicely readable, and we're going to be refactoring the exporter command soon anyway. Let's ship it. 😁

[rgildein]

I thought that we agree that custom metrics will go to the charm and not snap, or not?

[Deezzir]

I think we decided to leave them here for now

[gabrielcocenza]

I have the same impression as Robert that the custom metrics should happen at the charm. Moreover, I think this will require some logic at run_dcgm_exporter.sh that is current on #4 to detect if there is a .csv file (maybe be restrict with the naming of the file) and add the -f if necessary.