add swapAndLombardTransfer

[thal0x]

Adds swapAndLombardTransfer to the EurekaHandler contract.

The flow:

1. Transfer input token to contract
2. Swap input token for LBTC
3. Send relay fee (in LBTC) to relayer address
4. Wrap amountIn - fee to iLBTCv
5. Eureka transfer iLBTCv to Ledger

[mattac21]

why do we deduct the relay fee from the amount out here, when during the lombardTransfer function collect the fee but don't actually subtract it from the input amount. I'm assuming its some difference between lombardTransfer using safeTransferFrom(msg.sender, ...) and the swapAndLombardTransfer using safeTransfer to send the relay fee to the recipient, but not completely sure.