[OOC] IO Handler Performance Improvements and Generalization

[janniklinde]

This PR improves performance and generality of OOCMatrixIOHandler. We introduce experimental input/output streams that worked better in practice for OOC spilling in local experiments. We also introduce a lightweight OOCFuture to replace CompletableFuture in hot paths.

[codecov]

Codecov Report

❌ Patch coverage is 53.49794% with 226 lines in your changes missing coverage. Please review.
✅ Project coverage is 71.60%. Comparing base (85ea875) to head (a0cbd53).

Files with missing lines	Patch %	Lines
...time/ooc/cache/io/OOCBufferedDataOutputStream.java	46.30%	73 Missing and 7 partials ⚠️
.../org/apache/sysds/runtime/ooc/cache/OOCFuture.java	33.89%	72 Missing and 6 partials ⚠️
...ntime/ooc/cache/io/OOCBufferedDataInputStream.java	72.72%	28 Missing and 11 partials ⚠️
...sysds/runtime/ooc/cache/io/OOCMatrixIOHandler.java	57.44%	13 Missing and 7 partials ⚠️
...me/instructions/spark/data/IndexedMatrixValue.java	66.66%	4 Missing and 1 partial ⚠️
.../runtime/ooc/cache/io/SpillableObjectRegistry.java	75.00%	1 Missing and 2 partials ⚠️
...he/sysds/runtime/ooc/cache/io/SpillableObject.java	0.00%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #2532      +/-   ##
============================================
- Coverage     71.65%   71.60%   -0.05%     
- Complexity    49328    49395      +67     
============================================
  Files          1580     1585       +5     
  Lines        190516   190967     +451     
  Branches      37364    37424      +60     
============================================
+ Hits         136507   136746     +239     
- Misses        43486    43660     +174     
- Partials      10523    10561      +38     

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