Tokenize endpoint for rerank calculator

[przepeck]

🛠 Summary

CVS-178256
Tokenize endpoint for rerank models. Changes in README to change models to models from OV organization.

Docs: https://openvino-doc.iotg.sclab.intel.com/rerank_tokenize/model-server/ovms_demos_rerank.html

🧪 Checklist

• Unit tests added.
• The documentation updated.
• Change follows security best practices.
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[Copilot]

Pull request overview

This PR adds a tokenize endpoint for rerank models and updates documentation to reference models from the OpenVINO organization instead of other sources.

Changes:

• Adds tokenize endpoint support to the rerank calculator with configurable padding and truncation parameters
• Removes old demo configuration files (graph.pbtxt and config.json) from the rerank demo
• Updates documentation to reference OpenVINO organization models

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/test/reranknode_test.cpp	Adds comprehensive test coverage for the new tokenize endpoint including positive and negative test cases
src/rerank/rerank_calculator_ov.cc	Implements tokenize endpoint logic in the rerank calculator
src/rerank/BUILD	Adds dependency on tokenize_parser library
demos/rerank/models/graph.pbtxt	Removes old graph configuration file
demos/rerank/config.json	Removes old config file
demos/rerank/compare_results.py	Updates default model name in help text to match actual default value
demos/rerank/README.md	Updates model references to OpenVINO organization and adds tokenize endpoint documentation
demos/embeddings/README.md	Removes release version information from tokenize endpoint header

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