Update module_name in metadata

[ctreatma]

This module currently defines a generic value for module_name in the provider metadata: https://github.com/equinix-labs/terraform-equinix-aviatrix-edge/blob/main/main.tf#L13-L16

Updating the module_name to something more specific (for example, equinix-aviatrix-edge) will make it easier to track module usage, since the module_name is included in the User-Agent by the terraform provider.