feat: add pinot function registry to translate functions

[aaron-steinfeld]

Change Motivation: Query service is an abstraction over one or more data stores, but currently the abstract query requires implementation-specific function names. This function converter relaxes that constraint, and converts abstract functions (which, as of this change, are mostly the same as pinot-specific functions, with the exception of percentile and count) into functions compatible with pinot. This will allow us to remove some pinot-bound logic in gateway service (which previously did this conversion - we include logic here to unwind that for backwards compatibility), as well as add an upcoming feature, attribute projection, in such a way that the projection logic is not coupled to a specific data store.

[codecov]

Codecov Report

Merging #21 into main will increase coverage by 1.05%.
The diff coverage is 93.90%.

@@             Coverage Diff              @@
##               main      #21      +/-   ##
============================================
+ Coverage     73.83%   74.89%   +1.05%     
- Complexity      261      283      +22     
============================================
  Files            27       29       +2     
  Lines          1093     1151      +58     
  Branches        141      140       -1     
============================================
+ Hits            807      862      +55     
- Misses          230      233       +3     
  Partials         56       56              

Flag	Coverage Δ	Complexity Δ
#unit	74.89% <93.90%> (+1.05%)	283.00 <25.00> (+22.00)

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Impacted Files	Coverage Δ	Complexity Δ
...org/hypertrace/core/query/service/ConfigUtils.java	75.00% <75.00%> (ø)	1.00 <1.00> (?)
...rvice/pinot/converters/PinotFunctionConverter.java	92.98% <92.98%> (ø)	21.00 <21.00> (?)
.../query/service/pinot/PinotBasedRequestHandler.java	69.14% <100.00%> (+0.76%)	65.00 <2.00> (+2.00)
...service/pinot/QueryRequestToPinotSQLConverter.java	85.10% <100.00%> (+0.04%)	51.00 <1.00> (-2.00)	⬆️

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[buchi-busireddy]

Nice.. Thanks for cleaning this up!

[aaron-steinfeld]

No problem. Once this is up and running, we can do some clean up on the gateway side to strip the conversion there since this handles it now.

[aaron-steinfeld]

Change Motivation: Query service is an abstraction over one or more data stores, but currently the abstract query requires implementation-specific function names. This function converter relaxes that constraint, and converts abstract functions (which, as of this change, are mostly the same as pinot-specific functions, with the exception of percentile and count) into functions compatible with pinot. This will allow us to remove some pinot-bound logic in gateway service (which previously did this conversion - we include logic here to unwind that for backwards compatibility), as well as add an upcoming feature, attribute projection, in such a way that the projection logic is not coupled to a specific data store.