Extend `Path` type with `dependsOn` field, so that the sending logic will know whether to wait for the result of dependent tx before placing this transaction

[saledjenic]

When calculating the best route the router should select which transaction depends on which one and later when sending the sending logic must obey that.

The need for this is because some sending types (like swap (paraswap)) require a fully executed approval, not only submitted at the moment of building transaction, which means that the router has to mark such Paths as dependant and later send logic has to monitor on the approval execution before proceeding with building/sending dependant transactions.

Potentially we don't need (cause the logic is fully on our side), but we can follow the same logic (just to be uniform) for setting an approval for bridge transactions.