Remove aggregator-parent

Remove aggregator-parent

Unfortunately aggregator-parent can’t install or deploy itself, which
means it’s unusable outside odlparent. To avoid creating false hopes,
this patch removes aggregator-parent and adds two properties to
odlparent-lite to make it simpler to disable the corresponding
plugins.

Change-Id: I48705f7de0d8126818a4f16379e7775136b6e76c
Signed-off-by: Stephen Kitt <skitt@redhat.com>