feat: Add ContextRelevanceEvaluator to RAG eval harness

[shadeMe]

Proposed Changes:

This PR adds support for using the ContextRelevanceEvaluator component with the RAG evaluation harness.

How did you test it?

Unit tests

Checklist

• I have read the contributors guidelines and the code of conduct
• I have updated the related issue with new insights and changes
• I added unit tests and updated the docstrings
• I've used one of the conventional commit types for my PR title: fix:, feat:, build:, chore:, ci:, docs:, style:, refactor:, perf:, test:.
• I documented my code
• I ran pre-commit hooks and fixed any issue

[coveralls]

Pull Request Test Coverage Report for Build 9565496957

Details

• 98 of 99 (98.99%) changed or added relevant lines in 3 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.2%) to 97.696%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
test/evaluation/harness/rag/test_harness.py	95	96	98.96%

Totals
Change from base Build 9564589848:	0.2%
Covered Lines:	721
Relevant Lines:	738

---

💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 9565655224

Details

• 104 of 105 (99.05%) changed or added relevant lines in 3 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.7%) to 98.118%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
test/evaluation/harness/rag/test_harness.py	101	102	99.02%

Totals
Change from base Build 9564589848:	0.7%
Covered Lines:	730
Relevant Lines:	744

---

💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 9565831835

Details

• 99 of 99 (100.0%) changed or added relevant lines in 3 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.8%) to 98.238%

---

Totals
Change from base Build 9564589848:	0.8%
Covered Lines:	725
Relevant Lines:	738

---

💛 - Coveralls