Performance test build

[pavel-bc]

New Endpoints

• Create /block-index/:hash endpoint serving block + txs
• Create /mempool/txs with detailed tx information (limit to 50 txs)
• Create /multiaddr/:address endpoint for multiaddr input
• Add latest 50 txs in /multiaddr/:address output
• Add xpub integration to /multiaddr/:address
• Derive until 20 empty addresses found in a row

Updated Endpoints

• Add txids to /blocks/tip/hash endpoint
• Add latest 50 txs in /block-height/:height output
• Add balance to /address/:address/txs endpoint
• Add multiaddr & xpub support to /address/:address[/utxo]