Add additional GET RPC endpoints

Problem: the stacks blockchain RPC interface for GET requests is limited compared the data exposed in bitcoin/etc and the rich data in Hiro's API.

With recent changes to the HTTP interface (https://github.com/stacks-network/stacks-core/tree/master/stackslib/src/net/api), it should be much easier to add more RPC endpoints to expose some generic data. Initially, i'm thinking something like:

• block data
• tx data
• address info

some comparable bitcoin-cli rpc commands: getblockhash getblock getrawtransaction gettxout

for the data exposed, i don't think it should be a requirement to be as detailed as the Hiro API - but i think should be enough to understand what is in a block, or what a tx is doing (as well as retrieving the block hash by a block height).

references: bitcoin RPC:

• https://developer.bitcoin.org/reference/rpc/getblockhash.html
• https://developer.bitcoin.org/reference/rpc/getblock.html
• https://developer.bitcoin.org/reference/rpc/getaddressinfo.html
• https://developer.bitcoin.org/reference/rpc/getrawtransaction.html
• https://developer.bitcoin.org/reference/rpc/gettxout.html

Hiro API:

• https://hirosystems.github.io/stacks-blockchain-api//#tag/Blocks/operation/get_block_by_hash
• https://hirosystems.github.io/stacks-blockchain-api//#tag/Blocks/operation/get_block_by_height
• https://hirosystems.github.io/stacks-blockchain-api//#tag/Blocks/operation/get_block_by_burn_block_hash
• https://hirosystems.github.io/stacks-blockchain-api//#tag/Transactions/operation/get_transaction_by_id
• https://hirosystems.github.io/stacks-blockchain-api//#tag/Transactions/operation/get_raw_transaction_by_id