Add a new property to restore the old behavior for local ACP computing

Following NXP-17798, the local ACL is always at the end.
This is due to this commit:
https://github.com/nuxeo/nuxeo/commit/cc9b7c5a0f82c622025900341dab4f7f22e8d9a3

This prevents any custom ACL to be at this position.
For example, a customer in 6.0 has the following order:

1. inherited
2. local
3. localGroup (the custom one)

In 7.10 (and later versions) it gives the following:

1. inherited
2. localGroup (the custom one)
3. local

The code responsible for this is in ACPImpl but this cannot be overriden through a contribution.