eth/gasprice: add query limit for FeeHistory to defend DDOS attack

[NathanBSC]

Add query limit to defend DDoS attack. Max allow 100 different percentiles in rewardPercentiles.

this PR is ported from bsc 2423

[NathanBSC]

I checked the failed golangci-lint, It's strange
and on my mac, it's ok

[AaronChen0]

Please rebase your commit. Your branch is 236 commits behind the master branch. And the return values of function FeeHistory was changed in this commit 1ec7af2

[fjl]

This new limit is not necessary because it is already covered by other limits. The percentiles have to be in increasing order, and < 100. It is therefore impossible to submit more than 100.

There was a bug in the validation until recently, but it got fixed in #28954 .

[buddh0]

This new limit is not necessary because it is already covered by other limits. The percentiles have to be in increasing order, and < 100. It is therefore impossible to submit more than 100.

the element of rewardPercentiles is type float64 now, not integer, so is it impossible to submit more than 100? @fjl

[karalabe]

LGTM

[holiman]

LGTM