Some hexa commands fails if a default resource group is set

[sinedied]

Describe the bug

If you used az configure --defaults group=<name> to define a default resource group for the az cli, all commands that do not define a resource group will fail.

I quickly tested a fix in hexa code, and forcing and empty resource group param (--resource-group '') to all command that do not define the --resource-group flag fixes the issue.

So all command should for a --resource-group param (even empty) to avoid issues with configured defaults.

Note: I'm unsure whether a double single quote '' works as an empty param on Windows, it needs to be checked.

[manekinekko]

Related #27