large tx may fail to send because of request size

Start in lbry/wallet/network.py at send_request and trace the broadcast path through lbry/wallet/manager.py, daemon.py, and wallet/rpc/session.py. Reproduce or inspect the blockchain.transaction.broadcast request with a large transaction; done means the request is handled successfully without the connection reset shown in the report.

2021-07-06 21:11:23,233 WARNING  lbry.wallet.network:135: Connection lost: spv17.lbry.com:50001
2021-07-06 21:11:23,234 WARNING  lbry.wallet.network:117: closing connection to spv17.lbry.com:50001
2021-07-06 21:11:23,238 ERROR    lbry.wallet.network:78: wallet server (spv17.lbry.com) reset connection upon our blockchain.transaction.broadcast request, json of 1 args is 1589678 bytes
2021-07-06 21:11:23,239 WARNING  lbry.wallet.network:86: connection to spv17.lbry.com:50001 lost
2021-07-06 21:11:23,248 WARNING  lbry.wallet.network:321: connection lost to spv17.lbry.com:50001
2021-07-06 21:11:23,401 ERROR    lbry.extras.daemon.daemon:701: error handling api request
Traceback (most recent call last):
  File "c:\users\thoma\documents\lbry-sdk\lbry\extras\daemon\daemon.py", line 693, in _process_rpc_call
    result = await result
  File "c:\users\thoma\documents\lbry-sdk\lbry\extras\daemon\daemon.py", line 4133, in jsonrpc_support_create
    await self.broadcast_or_release(tx, blocking)
  File "c:\users\thoma\documents\lbry-sdk\lbry\extras\daemon\daemon.py", line 5537, in broadcast_or_release
    await self.wallet_manager.broadcast_or_release(tx, blocking)
  File "c:\users\thoma\documents\lbry-sdk\lbry\wallet\manager.py", line 302, in broadcast_or_release
    await self.ledger.broadcast(tx)
  File "c:\users\thoma\documents\lbry-sdk\lbry\wallet\network.py", line 74, in send_request
    return request.result()
  File "c:\users\thoma\documents\lbry-sdk\lbry\wallet\rpc\session.py", line 483, in send_request
    raise result
  File "C:\Python37\lib\asyncio\selector_events.py", line 814, in _read_ready__data_received
    data = self._sock.recv(self.max_size)
ConnectionResetError: [WinError 10054] An existing connection was forcibly closed by the remote host```