Add customizable columns to incus storage list

[stgraber]

Similarly to incus list, incus image list, incus config trust list and others.

It would be good to have incus storage list also feature a customizable list of columns.

[sohamnair]

Hello, I am new to open source contribution and would love to have a go at it.

[stgraber]

Sure, assigned it to you!

[sohamnair]

could you please clarify this statement "feature a customizable list of columns". Like what do you expect exactly?

[stgraber]

If you look at incus list --help or incus image list --help, you'll see that they have a -c argument (flagColumn) which offers shorthand options for a variety of fields.

For incus storage list, the default column list should be the same we have currently, probably with the shorthands nDSdus. No need to add additional columns at this stage, adding the feature will at least make it easier for people to hide columns they don't want.