functionapp: List possible outbound IPs Command not returning complete list

az webapp show --resource-group --name --query outboundIpAddresses --output tsv

**About the Bug**
When the previous command is used against a function app, the returned IPs list is incomplete. This issue was encountered while trying to setup an NSG to protect another resource, adding the returned IPs to the allowed list didn't permit outgoing traffic from the Function App to access the network. By instead getting the outbound IPs from the "ifconfig.me" site and adding those, the NSG was able to permit the outgoing Function traffic to enter.

**Steps to Reproduce**
This issue can be reproduced by executing the above command with the proper values populated against a Function App. Then verify the results by using an NSG to block all traffic except the returned IPs.

**Expected behavior**
Command should successfully list ALL the possible outbound IPs.