Fix build and bugs around VPCID handling

[mikkeloscar]

This fixes several things.

• Fixes the build which broke in fix: Only works with default VPC #20
• Correctly sets the vpcID such that it's used when getting listing Internet Gateways
• Adds a check to prevent crashing in case no Internet Gateways are found
• Prevent caching during bootstrap which would prevent the controller from doing anything if started after a configmap with egress config is already in the cluster before the controller is started.
• Updates to use Go modules

[mikkeloscar]

👍

[szuecs]

👍