[Feature request]: Create a cmdlet Get-AzApiManagementProductByGroup

[ToMakeSense]

I noticed that we have Add-AzApiManagementProductToGroup and Remove-AzApiManagementProductToGroup, but if it's possible to create a cmdlet like Get-AzApiManagementProductByGroup to query the products by group Id/Name? for example I want to list all the products in "Developers" group, it's impossible at present.

Besides, I found the Access Control information isn't included in Get-AzApiManagementProduct--> PsApiManagementProduct Class, it's inconvenient. If Access Control information is included, it's possible to filter with pipe like below, in this situation, it's unnecessary to create a new cmdlet like Get-AzApiManagementProductByGroup

Get-AzApiManagementProduct -Context $ApimContext | Where-Object GroupName -EQ "Developers"

[cormacpayne]

@solankisamir Hey Samir, would you mind taking a look at this feature request?