Restore opcode gas costs from Ethereum

[palango]

Description

Draft implementation for celo-org/celo-proposals#367

Tested

• Adapted existing tests to new behaviour
• Added tests that exercise old expectations with g fork disabled
• Updated monorepo e2e tests

Related issues

• Fixes https://github.com/celo-org/celo-blockchain-planning/issues/23

Backwards compatibility

Changes introduced at hardfork.

[github-actions]

Coverage from tests in ./e2e_test/... for ./consensus/istanbul/... at commit 5a4541d

coverage: 48.1% of statements across all listed packages

coverage:  58.1% of statements in consensus/istanbul
coverage:  37.9% 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:  61.6% 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:  64.4% 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]

[codecov]

Codecov Report

Patch coverage: 67.61% and project coverage change: +1.08 🎉

Comparison is base (71bdbcf) 54.30% compared to head (2718ae5) 55.38%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2117      +/-   ##
==========================================
+ Coverage   54.30%   55.38%   +1.08%     
==========================================
  Files         692      675      -17     
  Lines      115642   113702    -1940     
==========================================
+ Hits        62795    62971     +176     
+ Misses      49014    46906    -2108     
+ Partials     3833     3825       -8     

Impacted Files	Coverage Δ
cmd/devp2p/internal/ethtest/transaction.go	0.00% <0.00%> (ø)
cmd/geth/chaincmd.go	0.00% <0.00%> (ø)
cmd/geth/config.go	0.00% <0.00%> (ø)
cmd/geth/main.go	21.39% <ø> (+0.91%)	⬆️
cmd/geth/usage.go	10.90% <ø> (ø)
cmd/utils/flags.go	2.56% <0.00%> (ø)
consensus/istanbul/utils.go	47.10% <ø> (+1.13%)	⬆️
contracts/currency/currency.go	55.00% <ø> (ø)
contracts/election/election.go	25.00% <ø> (ø)
contracts/epoch_rewards/epoch_rewards.go	88.88% <ø> (ø)
... and 58 more

... and 31 files with indirect coverage changes

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[gastonponti]

I think that we have a possibility of a refactor there. But other than that, the PR looks good