Tracking issue for the Redis JSON support

[PragmaTwice]

Motivation

After #1803, we have basic support of RedisJSON, but massive amount of commands remain unsupported:

• Add support for the JSON.ARRAPPEND command #1806
• Add support for the JSON.ARRINDEX command #1807
• Add support for the JSON.ARRINSERT command #1808
• Add support for the JSON.ARRLEN command #1809
• Add support for the JSON.ARRPOP command #1810
• Add support for the JSON.ARRTRIM command #1811
• Add support for the JSON.CLEAR command #1812
• Add support for the JSON.DEL command #1813
• Add support for the JSON.FORGET command #1814
• Add support for the JSON.MERGE command #1815
• Add support for the JSON.MGET command #1816
• Add support for the JSON.MSET command #1817
• Add support for the JSON.NUMINCRBY command #1818
• Add support for the JSON.NUMMULTBY command #1819
• Add support for the JSON.OBJKEYS command #1820
• Add support for the JSON.OBJLEN command #1821
• Add support for the JSON.RESP command #1822
• Add support for the JSON.STRAPPEND command #1823
• Add support for the JSON.STRLEN command #1824
• Add support for the JSON.TOGGLE command #1825
• Add support for the JSON.TYPE command #1826

We need to support all of these commands to make our JSON support more complete and powerful.

Other pull requests related to JSON:

• Add support of new command JSON.SET and JSON.GET #1803
• Add test cases for JSON.SET and JSON.GET #1828
• Support format options for JSON.GET #1840
• JSON: support basic legacy path #1829
• Add method to read JSON from storage for simplifying code #1843

Call for Contribution

Feel free to pick up any issue and finish it!

You can request to be assigned with any issue from this list and try to implement it.

How to implement

1. Check the RedisJSON document and the document for the specific command (e.g. JSON.SET)
2. Check the document of Kvrocks data structures design and Add support of new command JSON.SET and JSON.GET #1803 to understand how Kvrocks implements Redis data types upon RocksDB. (and also the document of jsoncons which is used in kvrocks to parse/serialize JSON.)
3. Add corresponding methods to types/json.h, types.redis_json.h/cc, and command interface (Parse and Execute function) to commands/cmd_json.cc. (Note: types/json.h is just wrapper functions of jsoncons library which is not related to storage, while types/redis_json.h is about how to encode/decode JSON from storage (IO operations))
4. Add corresponding C++ unit test cases and Golang unit test cases for your newly implemented command.
5. Open your pull requests and we will review them promptly!

[Kelvinyu1117]

I found that some of the commands were marked as deprecated in the Redis document, do you guys still want to support it?
For example:
JSON.RESP

[git-hulk]

@Kelvinyu1117 I think we can complete the active commands first and the deprecated commands are also good to support if users did have solid reasons. cc @PragmaTwice