[bug] Loan open validate func doesn't validate target asset upfront
handler_loan_open doesn't validate that it can recognize the TargetAsset, which leads a loan open to be swallowed after the initial Collateral -> Derived Asset swap. Also need to verify that fuzzy matching is properly enabled for TargetAsset, as the below indicator should have matched a valid pool.
Seen on stagenet: https://viewblock.io/thorchain/tx/424F0B9053928A4816FF13D4B2965301E028ED06BDA2C87FC6900A7843332DCE?network=stagenet