feat(sync-v2): Add both BlockchainStreamingClient and TransactionStreamingClient to manage streamings from the client side

[msbrogli]

Motivation

Even though streaming servers were implemented on separated classes, the clients were intertwined within the sync agent.

Acceptance Criteria

1. Add BlockchainStreamingClient to handle blockchain streamings.
2. Add TransactionStreamingClient to handle transaction streamings.
3. Rename until_first_block to last_block_hash in GET-TRANSACTION-BFS message.
4. Add first_block_hash parameter to GET-TRANSACTION-BFS message.
5. Besides the changes in the GET-TRANSACTION-BFS, the changes in this PR can be considered a refactor and no other behavior should be changed.
6. Add pydantic models to GET-NEXT-BLOCKS, BEST-BLOCK and GET-TRANSACTIONS-BFS payloads.

Checklist

• If you are requesting a merge into master, confirm this code is production-ready and can be included in future releases as soon as it gets merged

[codecov]

Codecov Report

Attention: 47 lines in your changes are missing coverage. Please review.

Comparison is base (4b04c9c) 85.01% compared to head (5b59091) 85.06%.

❗ Current head 5b59091 differs from pull request most recent head eab8986. Consider uploading reports for the commit eab8986 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #848      +/-   ##
==========================================
+ Coverage   85.01%   85.06%   +0.05%     
==========================================
  Files         271      275       +4     
  Lines       22389    22502     +113     
  Branches     3417     3434      +17     
==========================================
+ Hits        19034    19142     +108     
+ Misses       2678     2674       -4     
- Partials      677      686       +9     

Files	Coverage Δ
hathor/p2p/sync_v2/exception.py	100.00% <100.00%> (ø)
hathor/p2p/sync_v2/streamers.py	90.05% <100.00%> (+0.05%)	⬆️
hathor/p2p/sync_v2/payloads.py	94.44% <94.44%> (ø)
hathor/p2p/sync_v2/agent.py	78.42% <83.78%> (+2.89%)	⬆️
hathor/p2p/sync_v2/transaction_streaming_client.py	75.40% <75.40%> (ø)
hathor/p2p/sync_v2/blockchain_streaming_client.py	76.62% <76.62%> (ø)

... and 2 files with indirect coverage changes

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

The base branch was changed.