[evm] Use `slice` instead `map` to record stack info when taking snapshot

[Liuhaai]

What would you like to be added:

Todo1: Reinitiate a new statedb of snapshot when running each execution()

Todo2: Use slice instead map to record stack info when taking snapshot

Why is this needed:

• The snapshot is useless and can be cleared after running the execution. When the number of tx is large, the copy of a number of useless snapshot causes performance bad .

• It's unnecessary to use map to record the snapshot info, because the height of snapshot increases one by one.

• Todo 1 must be finished before Todo 2, because slice will be panic if the idx is incorrect.

potential codes in evmstatedbadapter.go to be improved:

contractSnapshot    map[int]contractMap
suicideSnapshot     map[int]deleteAccount
preimageSnapshot    map[int]preimageMap

func (stateDB *StateDBAdapter) clear()