* Rename dz member id field
The name of the struct is enough to make this implicit
* Rename dz member enum and struct
Rename ExpeditionMember to DynamicZoneMember
Rename ExpeditionMemberStatus to DynamicZoneMemberStatus
* Rename dz window packet structs
This makes it more clear the window may be used by any dynamic zone
system not just expeditions (live missions fill the window when
player doesn't have an active expedition).
* Rename dz window packet fields
Add common expedition base class
Use repository for zone and world expedition caching
World now stores members and leader as Member objects instead of ids
This improves readability of the caching methods and lets world cache
expedition dzs and members like zone. World also now caches expeditions
as unique_ptr which will be necessary for future dz callback lambdas
that capture 'this' so addresses don't change on cache vector resizes.
Move early empty shutdown and process rate rules to DynamicZone scope
This decouples the expired status check from expeditions into an
internal dz method that can be called by its owning system
Use internal dz messages to process duration and location changes
Add world DynamicZone class (later this will inherit from a base)
Add FindDynamicZoneByID to get dz from zone and world system caches
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
