csv output option

Originally reported at https://github.com/Azure/azure-cli/issues/12624 by @johanburati

Would be good to have a csv output option, so that we could easily extract fields using good old linux cli commands and without redoing any formatting of any kind.

Like in the example below the first field has space in it.

$  az account list-locations -o table
DisplayName           Latitude    Longitude    Name
--------------------  ----------  -----------  ------------------
East Asia             22.267      114.188      eastasia
Southeast Asia        1.283       103.833      southeastasia
Central US            41.5908     -93.6208     centralus
East US               37.3719     -79.8164     eastus
East US 2             36.6681     -78.3889     eastus2
West US               37.783      -122.417     westus

Would be good to have this:

$  az account list-locations -o csv
East Asia,22.267,114.188,eastasia
Southeast Asia,1.283,103.833,southeastasia
Central US,41.5908,-93.6208,centralus
East US,37.3719,-79.8164,eastus
East US,2,36.6681,-78.3889,eastus2
West US,37.783,-122.417,westus
North Central US,41.8819,-87.6278,northcentralus
South Central US,29.4167,-98.5,southcentralus

So we can do things like this:

 $  az account list-locations -o csv | awk -F, '{ print  $4" -> "$1 }'
eastasia -> East Asia
southeastasia -> Southeast Asia
centralus -> Central US
eastus -> East US
eastus2 -> East US 2
westus -> West US

I think this option could come handy sometimes.