fix: handlePlayerDataRespawnSync seemingly executes too late in the respawn process
This is the second fix around this. The first has a commit name: "fix: `PlayerData` lost on respawn if EC spawn not set"
ServerPlayerEntity.copyFrom was triggering a getDisplayName (it looked
like???) so, I've moved the handlePlayerDataRespawnSync to right after
the `new ServerPlayerEntity` ctor invoke, so that we can't miss it.
Note that the old mixin inject remains because `handleRespawnAtEcSpawn`
has to happen after the new ServerPlayerEntity's spawn gets set in the
`respawnPlayer` method. (this remains the location for
`PlayerRespawnCallback`'s invoke because more of the new
ServerPlayerEntity is constructed/populated at this stage.