Extends IVaultHandler allowing the use of ETH and WETH as collateral on the same contract.
Called once the contract it's deployed, sets the orchestrator as owner. It also sets the vault counter to 1 as 0 is reserved for empty objects.
Adds collateral to vault using ETH.
msg.value should be higher than 0. ETH is turned into WETH.
Removes not used collateral from collateral.
_amout should be higher than 0. WETH is turned into ETH.
Only accept ETH via fallback from the WETH contract.