service-function-dictionary grouping is redundant as it is defined

In file:

sfc-model/src/main/yang/service-function-forwarder-logical.yang

The grouping service-function-dictionary is already defined for the SFF configuration with the same name in file service-function-forwarder.yang. It was not desired to repeat the name nor reuse the same fields, so additionally to change the name, the following fields should be removed:

list sff-interfaces
leaf failmode

Additionally, in this grouping the grouping dpn-locator is used and it should be renamed to dpn-grouping since the dpn-id defined inside is not going to be defined as other locators.