Change JSON serialization to custom json.dumps (#31100)
* Change JSON serialization to custom json.dumps to prevent escaping of "<", ">", "&", "'"
* caller has control over the order, remove sort_key=True
* Move tojson into a proper function and expose a couple of other args
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Co-authored-by: jun.4 <jun.4@kakaobrain.com>
Co-authored-by: Matt <rocketknight1@gmail.com>