flashloan e2e test

[MartinquaXD]

This task should be tackled last in the flashloan support initiative.
If e2e tests covering some aspects of the whole flow got implemented during the feature development they can now be consolidated into 1 e2e test.

Elements that need to be tested / done in this test:

• set up the protocol and a few AMMs
• deploy a flashloan provider (depending on how hard this is to set up it can either be a regular flashloan provider - balancer, uniswap, etc - or perhaps another helper contract that is only used for testing)
• create an order with a flashloan hint in the appdata
• await the order getting executed (make sure that the user funds and AMM states are set up such that it's impossible to settle the trade without the flashloan)
• assert that the order got executed
• assert that the protocol indexed the settlement transaction correctly (DB should not store the helper contract as the solver that executed the address)