deth_ctf: Deployer won't be able to retrieve the actual address of the created vault

[Zinda-Lukman]

In factory::deployVault when creating a new vault, the address of the created vault is stored in a memory variable vaultAddress which is destroyed after function execution and deployer won't be able to retrieve the actual created address.

The lastDeployed variable would have been user to store this address but it not stored their.

impact

User won't be able to know the address of their vaults that they created.

recommendation

Consider storing the new address in the lastDeployed variable so that users can access it.

[0xdeth]

Duplicate of #4.