frontend ust type 2 txs for eip 1559 compatible chains and increase maxFeePerGas

[fredo]

I noticed that transactions being sent on ethereum via the frontend are legacy transactions. We should use type 2 transactions where possible and increase the maxFeePerGas by a factor of X (i.e. 1.5).
This would ensure that the transaction is verlikely to be included in the next 1-2 blocks while maintaining a fair gas price. (see agent code base for reference)