adding a parameter set to the Add-AzureSqlDatabaseServerFirewallRule cmdlet to allow the user to specify that they would like to allow all azure services access to the server.
Addressing comments from PR.
- Changed "AzureSpecialRuleAddress" to "AllowAzureServiceRuleAddress"
- Changed "AllAzureServicesSet" to "AllAzureServicesParameterSet"
renaming a variable for consistency.
Changing the parameter set name to AllowAllAzureServicesParameterSet
Making the rule name for the Allow All Azure Services parameter set to be optional.
Writing tests for optional rule name for Allow All Azure Services special rule.
Merge pull request #1608 from akromm/dev-firewallRule

Add Azure Service Parameter Set to New-AzureSqlDatabaseServerFirewallRule Cmdlet.