System platform module update - 2: module registration header

Moved #system #module #register / #unregister #API from internal headers to #external #header. Updated all modules for the same. This will make module registration operation independent of system internal data-structures.

#System update 30 ...
[commit ed2812b71215e933c9b1e477fa25d084451eb7ae]

Ethernet chassis update

Creating new #ethetnet #chassis handler #API in ethernet module, for #register ing/ #unregister ing chassis #entity from #system module.

Ethernet update 36 ...
[commit 0e4f82eb011c950c930faba4ce01cc4b5658cbda]