LAG upgrade - 28: added LAG interface OPER-STATUS handler

Added #aggregator logical-interface ( #lag-interface ) #OPER-STATUS #handler routine in LAG module. This enables to #perform the #support #procedures for #lag-interfaces on OPER-STATUS change. The handler is registered with the IF module and #IF #module will #execute this #call-back on respective #parameter #change in IF module. This helps to perform the necessary procedures in LAG module when the OPER-STATUS is changed from IF module. The references to the augmented custom aggregator data-structures has been updated to the standard aggregator data-structures.

#LAG update 36 ...
[commit 53be9578d6d937bfe18fad3d7c1efffc69722550] (https://github.com/nes-repo/NES-Open-Switch/commit/53be9578d6d937bfe18fad3d7c1efffc69722550)

IF update - 13: updating logical interface status handler

Updated the #logical-interface #hierarchical #status #handling routines in IF module. The #status #change #handler routines has been #upgraded for the new data-structure changes. The hierarchical status handler #propagate s the interface #status #from the #lower interface #layer s #to the #higher #layer s. The interface #stacking enables the interface status to be decided based on the lower layer component interfaces. The interface status will depend on it's own #ADMIN-STATUS, #interface-type dependent #procedure s and #lower layer #interface #OPER-STATUS.

#IF update 13 ...
[commit 742604fca8f7d8c60f7e88afe52c7de58c33fc90] (https://github.com/nes-repo/NES-Open-Switch/commit/742604fca8f7d8c60f7e88afe52c7de58c33fc90)