Updates the L3 outbound firewall rules for a Cisco Meraki MX network.

Target: Meraki integration target or HTTP Endpoint for "api.meraki.com" with a path of "/api"

Account Key: None if using an integration-provided target, API token if using an HTTP Endpoint target

Steps:
[] Build the authorization header
[] Remove the default rule (it's recreated by default)
[] Update the rule list
[] Check if the request was successful:
[]> If it was, extract the new rule list and set the output variables
[]> If it wasn't, return an error

More information about this API: https://developer.cisco.com/meraki/api-v1/#!update-network-appliance-firewall-l-3-firewall-rules

Cisco Meraki - Appliance - Update L3 Outbound Firewall Rule