Add missing API call definitions and types

[aaroncox]

https://eos.greymass.com/v1/node/get_supported_apis

Missing as of Nov 2023 (3.x)

• /v1/chain/get_block_info
• /v1/chain/get_code
• /v1/chain/get_code_hash
• /v1/chain/get_currency_stats
• /v1/chain/get_producers
• /v1/chain/get_raw_abi
• /v1/chain/get_raw_code_and_abi
• /v1/chain/get_required_keys
• /v1/chain/get_scheduled_transactions
• /v1/chain/get_transaction_id
• /v1/chain/push_block
• /v1/chain/push_transactions

[aaroncox]

Some progress on adding new APIs in #59