Add helpers to create per-aggregate filters

This patchset introduce a new file of utility methods
to deal with aggregate metadata.
As well it updates related filters to use this new logic.
* AggregateRamFilter
* AggregateCoreFilter,
* AggregateTypeAffinityFilter

Closes-Bug: #1301340
Change-Id: I5e4aebe9e61cfbdc7b9e6b5de0788fc6670eb936
Merge "Add helpers to create per-aggregate filters"