R1:9f8907ccf7f3

Make Owners behavior when multiple packages own the same path with different dominion rules more consistent

Summary:
Fixes T12789. See that task for discussion. Currently, when multiple packages own the same path but have different dominion rules we get some weird/aribtrary/inconsistent results.

Instead, implement these rules:

- If zero or more weak and one or more strong packages claim a path, the strong packages (exactly) all own it.
- If one or more weak packages and zero strong packages claim a…