Experimental download code

[ogenev]

Merging my experimental download code to a new branch.

The code loads the CSV file with block hashes from block 14,000,000 till The Merge (15,537,393) and starts to request from the network block bodies and receipts in a configurable number of batches. When all data from the current batch is downloaded. it proceeds to the next batch of blocks.

TO switch between find content with census and peer scoring and recursive find content queries without census, set the CENSUS const (true for census, false - no census).
A hacky OfferReport is used for peer scoring as a shortcut but can also represent a FIndContent failure.).

The CSV data set can be downloaded from here and needs to be placed in the trin-history/src folder.

To run the downloader, just start Trin with the history network enabled.

Notes:

• running the script without a full view of the network and peer scoring is faster. (This may be due to a difference in the recursive find content and native find content implementations in Trin, or due to some inefficiencies in the downloader code. Needs more investigation.)
• a reasonable BATCH_SIZE is 20-30 blocks per batch (40-60 content types), bumping this number higher than 40-50 blocks will cause Trin's uTP to stale.