aaa: Changing of ExternalId to String

The following patch changes all occurances of external id to string.
The format of external id will be now
external id == internal id.
The format should be revised later on.

Topic: AAA
Change-Id: I086e6be2e47518238f2011702ee9ef17071fc2b6
Signed-off-by: Yair Zaslavsky <yzaslavs@redhat.com>