Improve JsonRecordPacker for performance

[yunzheng]

The JsonRecordPacker is used to serialize Records to JSON, which is used by elastic adapter as well.

Making this more performant would benefit the throughput to Elastic. It would be nice to:

• Add performance benchmark via pytest-benchmark and pytest-codspeed.
• Check if we can refactor JsonRecordPacker to also use JSONEncoder for more efficient encoding for certain types (see also Fix JsonRecordPacker for boolean fieldtype #205)
• Check if we can use a third party JSON module that is more performant, such as orjson or other modules.

Having a benchmark would be nice to test the different JSON modules.