Standardise reuse variable from project module and implement for net-vpc (#3205)

* exposing the network_id from the net-vpc module for use with tag bindings

* convert vpc_create to vpc_reuse

* Changed the reuse vars to standardised attributes

* fixed readme tests and schemas

* modified apigee blueprint to use vpc_reuse with network_id passthrough

---------

Co-authored-by: Ludovico Magnocavallo <ludomagno@google.com>

modules/project/service-agents.tf

@@ -18,7 +18,7 @@
 
 locals {
   services = distinct(concat(
-    local.available_services, try(var.project_reuse.project_attributes.services_enabled, [])
+    local.available_services, try(var.project_reuse.attributes.services_enabled, [])
   ))
   _service_agents_data = yamldecode(file("${path.module}/service-agents.yaml"))
   # map of api => list of agents