Obsoletable mounts and hulls

**What do you want to see?**
The ability to add a Family field to mounts and hulls to allow them to obsolete each other.

**How would it help players?**
Modders could create levelable mounts and hulls.

**Alternatives**
N/A

**Screenshots and mockups**
N/A

**Things to consider**
N/A

The issue names mounts and hulls but no files, tests, or entry points. Start by locating the mount and hull data models and the existing obsolescence logic. Done means mounts and hulls can share a Family field and modders can use it to create levelable variants.

Written by the indexing model from the issue text.