contrib: use batched JSON-RPC in linarize-hashes
contrib: use batched JSON-RPC in linarize-hashes

Batch up to 10000 requests for a ~30x speedup.

Crowndev/crowncoin,syscoin/syscoin,Crowndev/crowncoin,domob1812/crowncoin,domob1812/crowncoin,domob1812/crowncoin,syscoin/syscoin,Crowndev/crowncoin,Infernoman/crowncoin,syscoin/syscoin,Crowndev/crowncoin,domob1812/crowncoin,Infernoman/crowncoin,domob1812/crowncoin,syscoin/syscoin,syscoin/syscoin,Infernoman/crowncoin,syscoin/syscoin,Infernoman/crowncoin,Crowndev/crowncoin,domob1812/crowncoin,syscoin/syscoin,syscoin/syscoin,Infernoman/crowncoin,Crowndev/crowncoin,Infernoman/crowncoin