Connector RPC Introspection Checks

[Lohann]

Feature description
The chain's connectors must validate if it is connected to the right chain, this can be done by verifying the genesis block and forked blocks, example:

Genesis Block Validation

In the BlockchainConfig include a new optional parameter genesis_block which is the hash of genesis block:

• The client when connects to the RPC node, must retrieve the genesis block and verify if it matches the configured one
• Local testnets doesn't need to do this verification

Checkpoint Block validation

For forked chains, such as Ethereum Classic or Bitcoin Cash verifying the genesis block is not sufficient, so for all connectors we need to store in the latest finalized block number and hash, and verify that.

• Save a block number and hash of the latest known finalized block from of each chain in the BlockchainConfig.
• When the client connects to the RPC node, it must
• except for testnets.

Steps to reproduce
1 - Starts the ethereum connector using goerli network
2 - Connects to ethereum mainnet.
3 - The connectors works fine.

Expected output
The connector should return an meaniful error when the config and the RPC network doesn't match.

• All livenet connectors (ethereum mainnet, polkadot mainnet, etc) validates the genesis block
• All livenet connectors validates the checkpoint block
• unit tests for all the cases above