This should eliminate race conditions caused by zones trying to set
a leader when members in different zones quit at the same time
Zone still detects when leader goes offline to trigger a change
since it's easier than having world process expedition member status
updates and perform expedition lookups
This exposes dynamic zone ids for any future changes and will make it
easier to preserve historic dz and expedition data. This also cleans up
some dynamic zone creation for expedition requests
When purging instances the expedition table is no longer updated
since dynamic zone ids are not re-used like instance ids are
Update #dz list commands to show dz id
Add GetDynamicZoneID and get_expedition_by_dz_id quest apis