feat: ragas evals CLI (#2086)

```bash
❯ ragas evals test_app/evals/app_eval.py --dataset rag_dataset --metrics accuracy,fail_or_pass
Running evaluation: test_app/evals/app_eval.py
Dataset: rag_dataset
Getting dataset: rag_dataset
✓ Loaded dataset with 30 rows
✓ Completed experiments successfully
╭────────────────────────── Ragas Evaluation Results ──────────────────────────╮
│ Experiment: vibrant_naur                                                     │
│ Dataset: rag_dataset (30 rows)                                               │
╰──────────────────────────────────────────────────────────────────────────────╯
  Numerical Metrics
┏━━━━━━━━━━┳━━━━━━━━━┓
┃ Metric   ┃ Current ┃
┡━━━━━━━━━━╇━━━━━━━━━┩
│ accuracy │   0.933 │
└──────────┴─────────┘
         Categorical Metrics
┏━━━━━━━━━━━━━━┳━━━━━━━━━━┳━━━━━━━━━┓
┃ Metric       ┃ Category ┃ Current ┃
┡━━━━━━━━━━━━━━╇━━━━━━━━━━╇━━━━━━━━━┩
│ fail or pass │ fail     │      26 │
│              │ pass     │       4 │
└──────────────┴──────────┴─────────┘
✓ Experiment results displayed
✓ Evaluation completed successfully
```

```bash
❯ ragas evals test_app/evals/app_eval.py --dataset rag_dataset --metrics accuracy,fail_or_pass --baseline suspicious_babbage
Running evaluation: test_app/evals/app_eval.py
Dataset: rag_dataset
Baseline: suspicious_babbage
Getting dataset: rag_dataset
✓ Loaded dataset with 30 rows
✓ Completed experiments successfully
Comparing against baseline: suspicious_babbage
╭────────────────────────── Ragas Evaluation Results ──────────────────────────╮
│ Experiment: pedantic_mccarthy                                                │
│ Dataset: rag_dataset (30 rows)                                               │
│ Baseline: suspicious_babbage                                                 │
╰──────────────────────────────────────────────────────────────────────────────╯
                Numerical Metrics
┏━━━━━━━━━━┳━━━━━━━━━┳━━━━━━━━━━┳━━━━━━━━┳━━━━━━┓
┃ Metric   ┃ Current ┃ Baseline ┃  Delta ┃ Gate ┃
┡━━━━━━━━━━╇━━━━━━━━━╇━━━━━━━━━━╇━━━━━━━━╇━━━━━━┩
│ accuracy │   0.900 │    1.000 │ ▼0.100 │ fail │
└──────────┴─────────┴──────────┴────────┴──────┘
                  Categorical Metrics
┏━━━━━━━━━━━━━━┳━━━━━━━━━━┳━━━━━━━━━┳━━━━━━━━━━┳━━━━━━━┓
┃ Metric       ┃ Category ┃ Current ┃ Baseline ┃ Delta ┃
┡━━━━━━━━━━━━━━╇━━━━━━━━━━╇━━━━━━━━━╇━━━━━━━━━━╇━━━━━━━┩
│ fail or pass │ fail     │      26 │       25 │    ▲1 │
│              │ pass     │       4 │        5 │    ▼1 │
└──────────────┴──────────┴─────────┴──────────┴───────┘
✓ Comparison completed
✓ Evaluation completed successfully
```

---------

Co-authored-by: jjmachan <jamesjithin97@gmail.com>

Author: shahules786

experimental/pyproject.toml

@@ -47,6 +47,9 @@ platform = "ragas_experimental.project.backends.platform:PlatformProjectBackend"
 include = ["ragas_experimental*"]
 exclude = ["site*", "old_nbs*", "experiments*", "_proc*", "build*", "dist*"]
 
+[project.scripts]
+ragas = "ragas_experimental.cli:app"
+
 [tool.setuptools_scm]
 root = ".."  # Points to monorepo root, one directory up
 version_file = "ragas_experimental/_version.py"  # Creates a version file