Introduce DelegatingModificationApplyOperation
As it turns out implementations outside of SchemaAwareApplyOperation
can share implementations of most methods through delegation. Create
two new abstract classes, DelegatingModificationApplyOperation and
FullyDelegatedModificationApplyOperation which host partial and full
set of methods implemented as delegates.
FullyDelegatedModificationApplyOperation is used by AlwaysFailOperation
and RootModificationApplyOperation, as they the always-fail behaviour
is easily implemented through throwing ISE in delegate().
This eliminates 1-2 implementations of each ModificationApplyOperation
method.
Change-Id: I578769418baafb285593fefe8868e97e1d171157
JIRA: YANGTOOLS-944
Signed-off-by: Robert Varga <robert.varga@pantheon.tech>