Inspired by this bugzilla, https://bugzilla.redhat.com/show_bug.cgi?id=1949626

Currently, the AWS provider will not allow the creation of MachineSets when it doesn't know about the region being requested. The workaround for this is to allow the user to set a custom endpoint for the region they wish to use. Additionally, the aws-sdk module contains a list of known regions which it uses to validate the incoming request. When a user attempts to use a new AWS region, the client should be more tolerant about accepting the unknown region(without a custom endpoint) and instead emit a warning through the validating webhook to inform the user that the region might not exist.

DoD

• AWS provider allows MachineSet creation with regions that it doesn't validate from the aws-sdk
• AWS provider validating webhook checks the region and emits a warning if it is unrecognized. this warning should inform the user that the region is not recognized and no custom endpoint has been set.
• add unit tests to exercise this functionality
• check documentation for accuracy around region usage