generate contract bindings for flashloan helper

[MartinquaXD]

Flashloan support will require the driver to encode a transaction calling a new helper contract instead of the settlement contract directly.

In order to use the contract in the rust code base we need to generate bindings for it and add it to the drivers infra::blockchain::Contracts struct.
Although in practice there will only be 1 helper contract deployed and whitelisted in the protocols Authenticator contract the driver still needs to have this address passed in via a configuration parameter.
The reason is that this allows us to work even with contracts which don't have deterministic deployment (which results unstable addresses in our e2e tests).
Additionally we'll likely only get a preliminary contract early on for testing. The final contract may deviate from the original one due to necessary security changes or gas optimizations.