Important

Adds a new route to count datapoints in a dataset, replacing deprecated functionality, with updated handlers and tests.

• Behavior:
  • Adds GET /internal/datasets/{dataset_name}/datapoints/count route in internal.rs to return datapoint count, optionally filtered by function name.
  • Replaces count_datapoints_for_dataset_function with count_datapoints_for_dataset in dataset_queries.rs.
• Handlers:
  • Implements get_datapoint_count_handler in get_datapoint_count.rs.
• Tests:
  • Adds E2E tests in datapoint_count.rs to verify new route functionality.
• Removals:
  • Deletes CountDatapointsForDatasetFunctionParams.ts and related code.
• Misc:
  • Updates TensorZeroClient in tensorzero.ts to use new route for datapoint count.
  • Removes deprecated route from routes.ts.

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