Utilize new API for Public IPs

**Resource Provider**
Az.Network

**Description of Feature or Work Requested**
Please begin to use API 2020-08-01, which has a breaking change for public IP creation as described here: https://docs.microsoft.com/en-us/azure/virtual-network/create-public-ip-powershell?tabs=option-create-public-ip-standard-zones

That is, to create a standard zone-redundant public ip, you must now use -zone 1,2,3 in the parameter as opposed to not adding a zone parameter.

## Variables for the command ##
$rg = 'myResourceGroup'
$loc = 'eastus2'
$pubIP = 'myStandardZRPublicIP'
$sku = 'Standard'
$alloc = 'Static'
$zone = 1,2,3
New-AzPublicIpAddress -ResourceGroupName $rg -Name $pubIP -Location $loc -AllocationMethod $alloc -SKU $sku -zone $zone

If you do not add a zone parameter, the resource is created as non-zonal by default. This is different from how the current API and Powershell operate!

**Minimum API Version Required**
2020-08-01

**Target Date**
This cannot be applied until NRP 151 rolls out, which should complete over the month of September. But it should be applied to coincide with this rollout.

Also **need to know which Powershell version** will end up having this so we can update docs accordingly.

Start with the New-AzPublicIpAddress cmdlet and the linked Azure public IP documentation. Check how API version 2020-08-01 handles the zone parameter and determine which PowerShell version includes the change. Done means public IP creation follows the new standard zone-redundant behavior and the affected documentation identifies the correct PowerShell version.

Written by the indexing model from the issue text.