[wip] shared statedb triedb backends

[darioush]

Summary of decisions

• Uses runtime / global variables (gethtypes.MultiCoinEnabled) to enable RLP encoding of IsMultiCoin
• Uses upstream *state.StateDB to implement coreth's version.
• Uses upstream *trie.Database with coreth backends for hashdb / pathdb (this is because we have modifications compared to upstream)
• Uses upstream packages for trie, and most of core/state
• Supports the blockHash based snapshot that we use in coreth & subnet-evm
• Keeps the state key normalization as the client's responsibility (we can also make this have a runtime switch if we like)
• Shares some types with upstream