Provider a interface to get the transaction that use appointed cell

[yanguoyu]

For #354, we need to create a graph that links the cell from created to used. So we need to get the transaction that uses the appointed cell.

This interface may be like this:

• params: OutPoint
• result: If this cell is dead, return the transaction hash that uses the OutPoint cell, otherwise return null.

[Keith-CY]

This API works

https://mainnet-api.explorer.nervos.org/api/v2/ckb_transactions/0xd3125f76d7d6a83ba73d0fbaf2104b3ca1c3643122b0df373af0be4e07da2f75/display_outputs?page=1&page_size=10

If the cell is dead, consumed_tx_hash returns