[Graph] Support `deletedItems` APIs

[jiasli]

Related command
az ad

When deleting objects from Microsoft Graph, they are soft-deleted. They still count against the quota

https://docs.microsoft.com/en-us/azure/active-directory/enterprise-users/directory-service-limits-restrictions

A non-admin user can create no more than 250 Azure AD resources. Both active resources and deleted resources that are available to restore count toward this quota.

There are APIs for finding deleted objects and permanently (purge) them:

• List deletedItems (directory objects)
• Permanently delete item

Azure CLI should support deletedItems APIs.

[jiasli]

Currently this can be achieved by running az rest to call the REST API, like what we are currently doing in the tests:

azure-cli/src/azure-cli/azure/cli/command_modules/role/tests/latest/test_graph.py

Lines 133 to 135 in cac3f06

	# TODO: Add native commands for deleted items
	self.cmd("az rest --method DELETE "
	"--url https://graph.microsoft.com/v1.0/directory/deletedItems/" + object_id)