[minor_change] Add read-only pcTag, scope and segment attributes to aci_bridge_domain resource and datasource and add scope to aci_endpoint_security_group and aci_application_epg resources and datasources (DCNE-257)

[minor_change] Add read-only pcTag, scope and segment attributes to aci_bridge_domain resource and datasource and add scope to aci_endpoint_security_group and aci_application_epg resources and datasources (DCNE-257) #749