Use nonce as EOSEVM version and map to EVMC revision

[stephenpdeos]

The silkworm library handles the information of EVM revisions that needs to be activated at specific block heights by maintaining a static structure (ChainConfig) for each supported network.

In order to keep most of the silkworm code as it is we want to keep this structure, but change the way the active EVMC revision is obtained for the case of networks using the Trust Ruleset.

In this case (Trust Ruleset) the EVMC revision must be retrieved from the mapping of the EOSEVM version coming from the nonce field of the block header of the current block.

For other RuleSet, the current behavior should be mantained in order for tests to pass.

This is a WIP for the ChainConfig refactor:
https://github.com/eosnetworkfoundation/silkworm/tree/elmato/chain-config-refactor