Remove to/from json methods on typestates

[arminsabouri]

Now that we have proper session peristance in
0.24 we should remove these one off to/from json method as to descourage devs from creating their own custom peristance strategies.

Resolves #834

[coveralls]

Pull Request Test Coverage Report for Build 16002687643

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 85.487%

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Totals
Change from base Build 15983582431:	0.0%
Covered Lines:	7251
Relevant Lines:	8482

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💛 - Coveralls

[spacebear21]

code ACK.

To confirm my understanding: the session persister uses JSON internally when calling save/load? So implementers would provide e.g. a k/v store or SQL table with a JSON value column and the session persister would take care of de/serialization?

[arminsabouri]

code ACK.

To confirm my understanding: the session persister uses JSON internally when calling save/load? So implementers would provide e.g. a k/v store or SQL table with a JSON value column and the session persister would take care of de/serialization?

Yes, this is correct. More accurately the UniFFI exported Json Persister abstract class uses JSON internally in the save and load methods. We could also export other abstract classes that use different encodings (bincode, cbor, etc...)