WorldFactory: add sender to salt

[holic]

mud/packages/world/src/WorldFactory.sol

Line 36 in 52182f7

worldAddress = Create2.deploy(bytecode, worldCount++);

We should add msg.sender here as part of the salt, so the address is derived from the creator of the world. Even better might be a per address count or a custom salt in addition to the sender, so folks can attempt to deploy worlds across chains with the same address, regardless of how many they've deployed before.