[CLI] Add `llmtune inference [experiment_dir]`

[benjaminye]

The command llmtune inference [experiment_dir] aims to provide a versatile interface for running inference on pre-trained language models, allowing users to:

1. Load and run inference on a dataset; or
2. Provide arbitrary text inputs for inference for spot checks; or
3. Specify specific inputs to be injected in prompt template for inference

Proposed CLI

llmtune inference [experiment_dir] [options]

Arguments

experiment_dir: The experiment directory from finetuning experiments

Options

--dataset [dataset_path]: Path to a dataset (e.g., CSV, JSON, or Huggingface)
--text-input [text]: An arbitrary text input to run inference on. This option can be used for a single text input or for quick manual inference.
--column [name=value]: Allows specification of a column name and value for custom inputs. This option can be used multiple times to specify different column values.

Examples

Inference on a dataset:

llmtune inference ./my_experiment --dataset ./data/my_dataset.csv

Inference on arbitrary text:

llmtune inference ./my_experiment --text-input "This is an example text input for inference."

Inference with specific input values:

llmtune inference ./my_experiment --column column_1="foo" --column column_2="bar"

Related to: #160