* Update TpuConnection interface to be compatible with versioned txs
* Add convenience method for sending txs
* use parallel iterator to serialize transactions
(cherry picked from commit 016d3c450a)
Co-authored-by: Justin Starry <justin@solana.com>
* Add quic-client module to send transactions via quic, abstracted behind the TpuConnection trait (along with a legacy UDP implementation of TpuConnection) and change thin-client to use TpuConnection