fix: limit JSON payload size to 10MB

[de-sh]

Fixes #XXXX.

Description

Since #1100 we are using the Json extractor, which uses JsonConfig, not PayloadConfig

Testing

Send payload of size 5MB to the restricted endpoints, e.g. /api/v1/ingest

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This PR has:

• been tested to ensure log ingestion and log query works.
• added comments explaining the "why" and the intent of the code wherever would not be obvious for an unfamiliar reader.
• added documentation for new or modified features or behaviors.

[coveralls]

Pull Request Test Coverage Report for Build 12947359857

Details

• 0 of 7 (0.0%) changed or added relevant lines in 3 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 12.786%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/handlers/http/modal/ingest_server.rs	0	1	0.0%
src/handlers/http/modal/query_server.rs	0	1	0.0%
src/handlers/http/modal/server.rs	0	5	0.0%

Totals
Change from base Build 12943351293:	0.0%
Covered Lines:	2446
Relevant Lines:	19131

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💛 - Coveralls

[nikhilsinhaparseable]

looks good