[feat] Integrate new sources of data into `generate_data.py`

[maciejka]

There are new sources of utxo, previous timestamps and timestamp median being developed in #208 and #210.

Your task is to integrate them into generate_data.py script:

• previous timestamps from here should be used in this function
• utxo data from here should be used here. Note that the utxo data returned by get_utxo_set from #208 is per block so you should pass relevant information to the resolve_outpoint from fetch_block.

Don't just overwrite existing functions, rather add a parameter to the script which will allow to fetch data in both ways.

Although this issue is blocked by #208, #210 you can start right now by mocking necessary inputs.

[maciejka]

@lomasson I assigned you here, instead of #214 which is more suitable for a newcomer. Let me know if it is not ok for you.

[lomasson]

@maciejka Yes i can this one, no pb

[maciejka]

@lomasson please contact me on tg(@aundumla).