introduce edge machinepool for AWS Local Zone

[mtulio]

Machine Pool edge

• ensure a new machine pool edge is created
• ensure only AWS supports edge machine pool
• allow c5d.2xlarge instance to the pool (common between locations), and replace the default EBS to and gp2
• allow empty machine pool when LZ subnet is added
• allow replace the instance type
• allow replace the EBS type

Local Zone pools:

• ensure only zone type local-zone creates edge MachineSet
• ensure to fail when wavelength-zone zone type is added to the subnet list
• ensure the instance type is offered by the zone used to deploy on Local Zones

Documentation:

• network stack for UPI
• steps to create the cluster in existing VPC with local zones subnets