[Feature]: Add `Az.ResourceGraph` as dependency for `Az`

[o-l-a-v]

Description of the new feature

Az.ResourceGraph is used more and more, and some projects like EPAC (see below) has been bitten by it not being included when installing Az.

• https://github.com/Azure/enterprise-azure-policy-as-code/issues/596
• https://github.com/Azure/enterprise-azure-policy-as-code/issues/598
• https://github.com/Azure/enterprise-azure-policy-as-code/issues/601

This would also make sure that Az.ResourceGraph is available on solutions that includes the Az module, like with GitHub Actions workers.

Current dependencies can be seen like this:

• API: https://www.powershellgallery.com/api/v2/FindPackagesById()?id=%27Az%27&$filter=IsLatestVersion%20and%20not%20IsPrerelease
• PSResourceGet: (Find-PSResource -Repository 'PSGallery' -Name 'Az').'Dependencies'

Proposed implementation details (optional)

Add Az.ResourceGraph as dependency for Az so Az.ResourceGraph is installed when doing Install-Module -Name 'Az'.

[isra-fel]

The conversation with ResourceGraph team is still ongoing.