[SYSTEMDS-3780] Compression-fused quantization

[anuunchin]

This PR is part of the LDE project, addressing #3780.

What for?

To introduce a new instruction to fuse quantization and compression.

Given:

M2 = floor(M * S)
C = compress(M2)

This PR adds a rewrite and instruction that replaces the sequence with a new built-in function:
quantize_compress(M, S)

Currently covered

• Rewrite detection - Identifies multiplication, floor, and compress sequences.quantize_compress()
• Supports scalar and row-wise vector scale factors
• New reader that directly quantizes input data
• Some fast path compression scenarios that don't use readers
• Bitmap encoding that takes into account quantization (not full)
• Estimator that takes into account quantization (not full)

Further

• Component tests
• Extensive catches if not implemented on all levels
• Missing fast path compression implementation
• Enable full matrix scale factors
• Docs

[Baunsgaard]

Lots of very good things,

I have left a few comments, And i would like to see some performance numbers.

Specifically, with the fused operator vs without.

You can run it across various sizes, or distinct values after quantization.

[codecov]

Codecov Report

Attention: Patch coverage is 53.72425% with 292 lines in your changes missing coverage. Please review.

Project coverage is 72.41%. Comparing base (78b23cf) to head (92a99c1).

Files with missing lines	Patch %	Lines
...sds/runtime/compress/colgroup/ColGroupFactory.java	38.06%	85 Missing and 11 partials ⚠️
...ntime/compress/estim/encoding/EncodingFactory.java	58.23%	54 Missing and 17 partials ⚠️
...e/sysds/runtime/compress/bitmap/BitmapEncoder.java	46.91%	38 Missing and 5 partials ⚠️
...untime/compress/colgroup/ColGroupUncompressed.java	25.00%	26 Missing and 7 partials ⚠️
...apache/sysds/parser/BuiltinFunctionExpression.java	0.00%	15 Missing ⚠️
...time/instructions/cp/CompressionCPInstruction.java	76.00%	5 Missing and 7 partials ⚠️
...untime/compress/readers/ReaderColumnSelection.java	33.33%	5 Missing and 5 partials ⚠️
...s/rewrite/RewriteQuantizationFusedCompression.java	79.54%	5 Missing and 4 partials ⚠️
...in/java/org/apache/sysds/parser/DMLTranslator.java	0.00%	2 Missing ⚠️
.../sysds/runtime/instructions/InstructionParser.java	0.00%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #2226      +/-   ##
============================================
- Coverage     72.46%   72.41%   -0.06%     
- Complexity    45453    45563     +110     
============================================
  Files          1469     1471       +2     
  Lines        170893   171447     +554     
  Branches      33325    33488     +163     
============================================
+ Hits         123846   124158     +312     
- Misses        37630    37819     +189     
- Partials       9417     9470      +53     

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