[Drain Safe] Warn for those tokens with really low amount or USD value

[dasanra]

Overview

Currently the user can select which tokens to be transferred when draining a Safe. But many safes suffer of spam tokens or may have tokens with low amounts which are not interesting to transfer, because the transfer cost would be higher than the token value.

Goals

We should give the user some feedback to detect this tokens that may not be worth to transfer because the cost would be higher than the cost of moving them.

• We should compare for each token when the fiat value can overpass the transaction cost of transferring it
• Show a yellow warning sign ⚠️ or something similar next to the fiat value of the token.

Requirements

How to check that transfer value is higher than the fiat value?

• We can have an approximation of how much calling an ERC20 send will cost in terms of gas. This will be a fixed amount.
• We should fetch the gwei fast price for the chain at that moment so we can say if it could be more costly than current value
• We should fetch the fiat value of the token used to pay the transaction so we can compare the amount to the cost