Use orjson to de-/serialize json-rpc messages

[deathaxe]

After a recent discussion about json serialization performance, I was curious about impact orjson makes on LSP processing performance.

This PR showcases how orjson as transport de-/serializer.

During recent 2 weeks of daily use, I haven't realized any issues, but also my projects are small enough to not realize any significant impact on overall performance.

Maybe someone using heavy language servers such as typescript can try to benchmark it.

[predragnikolic]

It can be tested with this package that Rafal wrote
https://github.com/sublimelsp/LSP-performance-test

[deathaxe]

According to this plugin, orjson doesn't make any difference. Tests results in 0.189 - 0.192 with both json and orjson on my machine.

[predragnikolic]

This thread has some information of where bottle necks are located, and how they were solved
#2190

[deathaxe]

Yeah, and those include json serialization performance being an aspect. With promised performance of orjson I would have expected a little improvement with regards to deserialize messages from language servers. Maybe payload is just too small to outweight overhead for python->C/rust->python translations.

[rchl]

That test tests performance of our format_completion and not json deserialization. It would have to be modified.