config: fee param cleanup

[shaspitz]

• Removes red herring values in genesis.json that do not affect gas params.
• Explicitly sets miner.gasprice to default value value. miner.gasprice represents minimum priority fee from this line.
• Explicitly sets gpo.maxprice to default value, representing max priority fee that is suggested by gasPrice oracle.

[shaspitz]

I've confirmed rpc suggestions are as expected. Suggested priority fee is 1 gwei, 0-demand base fee is 7 wei:

shawn@Shawns-MacBook-Pro ~ % curl -X POST -H "Content-Type: application/json" --data '{"jsonrpc":"2.0", "method":"eth_maxPriorityFeePerGas", "params":[], "id":1}' http://localhost:8545
{"jsonrpc":"2.0","id":1,"result":"0x3b9aca00"}
shawn@Shawns-MacBook-Pro ~ % curl -X POST -H "Content-Type: application/json" --data '{"jsonrpc":"2.0","method":"eth_feeHistory","params":[10, "latest", []],"id":1}' http://localhost:8545
{"jsonrpc":"2.0","id":1,"result":{"oldestBlock":"0x1df","baseFeePerGas":["0x7","0x7","0x7","0x7","0x7","0x7","0x7","0x7","0x7","0x7","0x7"],"gasUsedRatio":[0,0,0,0,0,0,0,0,0,0]}}
shawn@Shawns-MacBook-Pro ~ % curl -X POST -H "Content-Type: application/json" --data '{"jsonrpc":"2.0", "method":"eth_gasPrice", "params":[], "id":1}' http://localhost:8545
{"jsonrpc":"2.0","id":1,"result":"0x3b9aca07"}
shawn@Shawns-MacBook-Pro ~ %

[shaspitz]

Signers do not finalize low tip txes as expected when this PR is rebased onto ethereum#28933