LAG upgrade - 22: updating aggregator activation handler

Updating the #aggregator #activation handler in LAG module. The references to the augmented aggregator data-structures has been updated to the standard aggregator data-structures. This allows to directly use the #standard #aggregator data-structure and use the #embedded custom aggregator data-structure for internal operations. The #status related parameters are kept in the custom data-structure and on aggregator status #change these are updated as #active / #not-in-service. When aggregator are not ready to participate in the normal operations because of inconsistency in the applied configuration the state is set as #not-ready.

#LAG update 30 ...
[commit e0fd07fb4b43c2c956e2d465b5383fef93871f06] (https://github.com/nes-repo/NES-Open-Switch/commit/e0fd07fb4b43c2c956e2d465b5383fef93871f06)