[pallet-revive] fee estimation fixes (#7281)

- Fix the EVM fee cost estimation.
The estimation shown in EVM wallet was using Native instead of EVM
decimals
- Remove the precise code length estimation in dry run call.
Over-estimating is fine, since extra gas is refunded anyway.
- Ensure that the estimated fee calculated from gas_price x gas use the
encoded weight & deposit limit instead of the exact one calculated by
the dry-run. Else we can end up with a fee that is lower than the actual
fee paid by the user

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Co-authored-by: command-bot <>