As a side effect, this moves the initial game server sync message into
the login code, since that's the first place we can check for admin
permissions and we want to avoid sending large messages to users who are
not authenticated (especially if the player cap has been reached;
previously, the player cap check limited the damage that could be done
by unauthenticated players).
Some fallout from this is that we don't synchronize the Player component
anymore, which had some minor effects on voxygen. This update also
breaks Torvus, since Client::new now expects the username and password
to be provided from the getgo--an accompanying MR will be submitted to
fix it.
* Added `LootOwner` component used to indicate that an `ItemDrop` entity is owned by another entity
* A loot winner is now calculated after EXP allocation using the EXP per entity for weighted chance distribution
* Used existing Inventory Full overitem text to show "Owned by {player} for {seconds}secs" when a pickup fails due to a loot ownership check
* Updated agent code to take into account loot ownership when searching for `ItemDrop` targets to pick up
* Added `loot` ECS system to clear expired loot ownerships
