Implemented eth namespace apis (almost returning dummy or fixed values)

[aeharvlee]

Proposed changes

This PR Implemented eth namespace apis.

• Added publicGovernanceAPI which is used by eth_etherbase, eth_coinbase. Those apis return the address of operating node.
• Other apis returns dummy or fixed values.

Api	Ethereum Source Code
eth_etherbase	Etherbase
eth_coinbase	Coinbase
eth_hashrate	Hashrate
eth_mining	Mining
eth_getWork	Mining
eth_submitWork	SubmitWork
eth_submitHashrate	SubmitHashrate
eth_getHashrate	GetHashrate
eth_getUncleByBlockNumberAndIndex	GetUncleByBlockNumberAndIndex
eth_getUncleByBlockHashAndIndex	GetUncleByBlockHashAndIndex
eth_getUncleCountByBlockNumber	GetUncleCountByBlockNumber
eth_getUncleCountByBlockHash	GetUncleCountByBlockHash

Related Confluence: How Ethereum APIs are supported in Klaytn

How to test this PR

First, please clone my origin repo.

1. Run added tests in this PR.

• Run go test -run "TestEthereumAPI_*" -v ./... -count=1

2. Build ken and test with it.

1. Build ken with source codes related with this PR.

• Run make ken

2. Run ken

• In my case, I tested with CN 1 - PN 1 - EN 1 in my local.
• Please note that you should enable eth namepsace to RPC_API and WS_API in kend.conf

Test Logs

Click to expand

➜  corecell curl http://localhost:8551 \
-X POST \
-H "Content-Type: application/json" \
-d '{"jsonrpc":"2.0","method":"eth_etherbase","params":[],"id":1}'
{"jsonrpc":"2.0","id":1,"result":"0x9d776ff5745fd5b0df455f3259008ff3cd0eba95"}

➜  corecell curl http://localhost:8551 \
-X POST \
-H "Content-Type: application/json" \
-d '{"jsonrpc":"2.0","method":"eth_coinbase","params":[],"id":1}'
{"jsonrpc":"2.0","id":1,"result":"0x9d776ff5745fd5b0df455f3259008ff3cd0eba95"}

➜  corecell curl http://localhost:8551 \
-X POST \
-H "Content-Type: application/json" \
-d '{"jsonrpc":"2.0","method":"eth_hashrate","params":[],"id":1}'
{"jsonrpc":"2.0","id":1,"result":"0x0"}

➜  corecell curl http://localhost:8551 \
-X POST \
-H "Content-Type: application/json" \
-d '{"jsonrpc":"2.0","method":"eth_mining","params":[],"id":1}'
{"jsonrpc":"2.0","id":1,"result":false}

➜  corecell curl http://localhost:8551 \
-X POST \
-H "Content-Type: application/json" \
-d '{"jsonrpc":"2.0","method":"eth_getWork","params":[],"id":1}'
{"jsonrpc":"2.0","id":1,"error":{"code":-32000,"message":"no mining work available yet"}}

➜  corecell curl localhost:8551 -X POST -H "Content-Type: application/json" --data '{"jsonrpc":"2.0", "method":"eth_submitWork", "params":["0x0000000000000001", "0x1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef", "0x1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef"],"id":73}'
{"jsonrpc":"2.0","id":73,"result":false}

➜  corecell curl http://localhost:8551 \
-X POST \
-H "Content-Type: application/json" \
-d '{"jsonrpc":"2.0","method":"eth_getHashrate","params":[],"id":1}'
{"jsonrpc":"2.0","id":1,"result":0}

➜  corecell curl http://localhost:8551 \
-X POST \
-H "Content-Type: application/json" \
-d '{"jsonrpc":"2.0","method":"eth_getUncleCountByBlockNumber","params":["0x1"],"id":1}'
{"jsonrpc":"2.0","id":1,"result":"0x0"}

➜  corecell curl http://localhost:8551 \
-X POST \
-H "Content-Type: application/json" \
-d '{"jsonrpc":"2.0","method":"eth_getUncleCountByBlockHash","params":["0xa4e7dcaedd5e5acb830180c2f05c5e95fb66908021623719c284dbf4c4262b40"],"id":1}'
{"jsonrpc":"2.0","id":1,"result":"0x0"}

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• Bugfix
• New feature or enhancement
• Others

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• Lint and unit tests pass locally with my changes ($ make test)
• I have added tests that prove my fix is effective or that my feature works
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Further comments

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[hqjang-pepper]

LGTM. Works same with Confluence doc spec.