fix(zetaclient): use outTxParams for the used amount in evm WithdrawTx

[lumtis]

Description

This fix is part of #980 but doesn't fix it completely. We need to add the actually payment of gas for ZETA withdraw. I'm currently investigating another bug in #991 where calling EVM in EVM post tx hook makes the node crashing.
I open this PR to get approval on this first fix.

Update in Zetaclient send.InboundTxParams.Amount.BigInt() to send.GetCurrentOutTxParam().Amount.BigInt() when signing txs to get the amount updated from the gas payment.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Include instructions and any relevant details so others can reproduce.

• Tested CCTX in localnet
• Tested in development environment
• Go unit tests
• Go integration tests
• Tested via GitHub Actions

Checklist:

• I have added unit tests that prove my fix feature works

[lumtis]

Closing since #991 now contains the full fix