test endpoints

[MACS-J1149]

• /account/balance
• /account/coins (not implemented)
• /block
• /block/transaction
• /call
• /construction/combine
• /construction/derive
• /construction/hash
• /construction/metadata
• /construction/parse
• /construction/payloads
• /construction/preprocess
• /construction/submit
• /events/blocks (not implemented)
• /mempool
• /mempool/transaction
• /network/list
• /network/options
• /network/status
• /search/transactions (not implemented)