Remove special handling for gas estimation

[palango]

This is now done by the SkipDebitCredit flag.

Resolves #2267

[github-actions]

Coverage from tests in ./e2e_test/... for ./consensus/istanbul/... at commit 8d0f0f9

coverage: 46.3% of statements across all listed packages

coverage:  56.8% of statements in consensus/istanbul
coverage:  23.7% of statements in consensus/istanbul/announce
coverage:  54.3% of statements in consensus/istanbul/backend
coverage:   0.0% of statements in consensus/istanbul/backend/backendtest
coverage:  24.3% of statements in consensus/istanbul/backend/internal/replica
coverage:  63.3% of statements in consensus/istanbul/core
coverage:  45.0% of statements in consensus/istanbul/db
coverage:   0.0% of statements in consensus/istanbul/proxy
coverage:  64.2% of statements in consensus/istanbul/uptime
coverage:  51.8% of statements in consensus/istanbul/validator
coverage:  79.2% of statements in consensus/istanbul/validator/random

[github-actions]

Test failures:
TestWalletNotifications: keystore Failed keystore_test.go:453: wallet list doesn't match required accounts: have 541, want 540 keystore_test.go:481: can&apos;t find event with Kind=0 for 98236cbb3fc0ed453f15c72f6b4fac460ef8d5c6</code></pre></td></tr>
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[piersy]

Hey @palango. I think this change is fine, but I think there is a problem with the previous change.

Looking in ethapi.DoCall:

celo-blockchain/internal/ethapi/api.go

Line 912 in 36746b2

evm, vmError, err := b.GetEVM(ctx, msg, state, header, &vm.Config{NoBaseFee: true, SkipDebitCredit: true})

We can see that skipDebitCredit is set to true, but ethapi.DoCall is called from ethapi.Call so that previous change is also disabling debit/credit calls for eth_call which I don't think we want, right? I think it makes sense to fix that here and also include a comment for EstimateGas saying that we skip the debit/credit calls.

[palango]

Hey @palango. I think this change is fine, but I think there is a problem with the previous change.

Looking in ethapi.DoCall:

celo-blockchain/internal/ethapi/api.go

Line 912 in 36746b2

evm, vmError, err := b.GetEVM(ctx, msg, state, header, &vm.Config{NoBaseFee: true, SkipDebitCredit: true})

We can see that skipDebitCredit is set to true, but ethapi.DoCall is called from ethapi.Call so that previous change is also disabling debit/credit calls for eth_call which I don't think we want, right? I think it makes sense to fix that here and also include a comment for EstimateGas saying that we skip the debit/credit calls.

I fixed that in #2273

[piersy]

Looking good!