chore!:drop JSON support on intermediate agg result

[PSeitz]

JSON support is flaky anyway due it's lack on f64::INF etc. handling

add support for other formats by removing skip_serialize and untagged

In conjunction with: quickwit-oss/quickwit#3170

[codecov-commenter]

Codecov Report

Merging #1992 (e4af61c) into main (80df1d9) will decrease coverage by 0.03%.
The diff coverage is 96.77%.

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@@            Coverage Diff             @@
##             main    #1992      +/-   ##
==========================================
- Coverage   94.35%   94.33%   -0.03%     
==========================================
  Files         320      320              
  Lines       59064    59024      -40     
==========================================
- Hits        55729    55679      -50     
- Misses       3335     3345      +10     

Impacted Files	Coverage Δ
src/aggregation/agg_tests.rs	100.00% <ø> (ø)
src/aggregation/mod.rs	93.90% <ø> (-2.78%)	⬇️
src/aggregation/intermediate_agg_result.rs	94.83% <96.15%> (-0.49%)	⬇️
src/aggregation/bucket/range.rs	96.23% <100.00%> (ø)
src/aggregation/bucket/term_agg.rs	97.95% <100.00%> (ø)

... and 1 file with indirect coverage changes

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[fulmicoton]

I am lacking background on this. What problem does it solve?

[PSeitz]

For sending intermediate results between nodes JSON is unnecessary brittle. It's easy to run into cases that are not supported without noticing.

Currently it fails sometimes for ddsketch deserialization, when there are f64 values with f64::INF, which serializes to null.
Same for f64::NAN serde-rs/json#202

I'd like to avoid any special de/serialization that can be handled by switching the format.
I tested serde round-trips on a similar data-structure here:

https://github.com/PSeitz/test_serde_formats

Format	Result
Json	Err(invalid type: null, expected f64 at line 1 column 81)
Postcard	Err(Found an Option discriminant that wasn't 0 or 1)
Ron	Ok(())
MessagePack	Err(invalid length 0, expected struct IntermediateAggregationResults with 2 elements)
Bincode	Err(invalid value: integer 10, expected variant index 0 <= i < 2)
Ciborium	Ok(())
Bson	Err(Invalid map key type: 10)

[fulmicoton]

Is the problem only NaN or is there something else?

[PSeitz]

Is the problem only NaN or is there something else?

For JSON it's NaN, INF,NEG_INF and non-string keys in Hashmaps. Maybe more we don't know yet