fix: use values in algo name map

[pinaraws]

Before:

>>> print(amazon_fmeval.EVAL_ALGORITHMS.keys())
dict_keys(['factual_knowledge', 'qa_accuracy', 'summarization_accuracy', 'prompt_stereotyping', 'classification_accuracy', 'general_semantic_robustness', 'summarization_accuracy_semantic_robustness', 'toxicity', 'qa_toxicity', <EvalAlgorithm.SUMMARIZATION_TOXICITY: 'summarization_toxicity'>, <EvalAlgorithm.CLASSIFICATION_ACCURACY_SEMANTIC_ROBUSTNESS: 'classification_accuracy_semantic_robustness'>])

After:

>>> print(amazon_fmeval.EVAL_ALGORITHMS.keys())
dict_keys(['factual_knowledge', 'qa_accuracy', 'summarization_accuracy', 'prompt_stereotyping', 'classification_accuracy', 'general_semantic_robustness', 'summarization_accuracy_semantic_robustness', 'toxicity', 'qa_toxicity', 'summarization_toxicity', 'classification_accuracy_semantic_robustness'])

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