support to enable Map encoded custom forward index

[raghavyadav01]

PR add support for enabling Custom MAP encoded forwarded index creator and reader.
Summary :

• immutable Segment Index Build Path

Collect MapColumnPreIndexStatsCollector during gather stats phase
Collect MAP encoded column custom metadata properties file and merge with segment metadata.properties file.

• Immutable Segment Loader Path

Initialize MAP column with child columns (keys)
Collect all the key level indexes into custom MAP column IndexContainer.
For MAP encoded columns initialize Custom Forward Index Reader with child column indexes buffer.

• Couple of MAP data column bug fixes

Fix MAP convert for segment upload use case.
Fix Dictionary Index reader API .

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 21.36752% with 92 lines in your changes missing coverage. Please review.

Project coverage is 63.69%. Comparing base (59551e4) to head (3439a27).
Report is 1679 commits behind head on master.

Files with missing lines	Patch %	Lines
.../segment/index/column/MapColumnIndexContainer.java	0.00%	18 Missing ⚠️
...egment/spi/index/metadata/SegmentMetadataImpl.java	0.00%	12 Missing ⚠️
...converter/stats/RealtimeSegmentStatsContainer.java	25.00%	8 Missing and 1 partial ⚠️
...ment/index/forward/ForwardIndexCreatorFactory.java	11.11%	7 Missing and 1 partial ⚠️
...ment/creator/impl/SegmentColumnarIndexCreator.java	22.22%	5 Missing and 2 partials ⚠️
...segment/spi/index/metadata/ColumnMetadataImpl.java	0.00%	7 Missing ⚠️
...ndex/converter/SegmentV1V2ToV3FormatConverter.java	0.00%	5 Missing and 1 partial ⚠️
...he/pinot/segment/spi/index/ForwardIndexConfig.java	16.66%	5 Missing ⚠️
...indexsegment/immutable/ImmutableSegmentLoader.java	55.55%	3 Missing and 1 partial ⚠️
...a/org/apache/pinot/common/utils/PinotDataType.java	0.00%	3 Missing ⚠️
... and 7 more

Additional details and impacted files

@@             Coverage Diff              @@
##             master   #15006      +/-   ##
============================================
+ Coverage     61.75%   63.69%   +1.94%     
- Complexity      207     1483    +1276     
============================================
  Files          2436     2717     +281     
  Lines        133233   152358   +19125     
  Branches      20636    23557    +2921     
============================================
+ Hits          82274    97046   +14772     
- Misses        44911    48001    +3090     
- Partials       6048     7311    +1263     

Flag	Coverage Δ
custom-integration1	100.00% <ø> (+99.99%)	⬆️
integration	100.00% <ø> (+99.99%)	⬆️
integration1	100.00% <ø> (+99.99%)	⬆️
integration2	0.00% <ø> (ø)
java-11	63.68% <21.36%> (+1.97%)	⬆️
java-21	63.54% <21.36%> (+1.91%)	⬆️
skip-bytebuffers-false	63.69% <21.36%> (+1.94%)	⬆️
skip-bytebuffers-true	63.52% <21.36%> (+35.80%)	⬆️
temurin	63.69% <21.36%> (+1.94%)	⬆️
unittests	63.69% <21.36%> (+1.94%)	⬆️
unittests1	56.19% <17.94%> (+9.30%)	⬆️
unittests2	34.02% <10.25%> (+6.29%)	⬆️

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