CLI: Expose chat template in data options (#1582)

## Describe your changes
Provide `--use_chat_template` option in the CLI to use the default chat
template instead of text_template or text_field.

## Checklist before requesting a review
- [ ] Add unit tests for this change.
- [ ] Make sure all tests can pass.
- [ ] Update documents if necessary.
- [ ] Lint and apply fixes to your code by running `lintrunner -a`
- [ ] Is this a user-facing change? If yes, give a description of this
change to be included in the release notes.
- [ ] Is this PR including examples changes? If yes, please remember to
update [example
documentation](https://github.com/microsoft/Olive/blob/main/docs/source/examples.md)
in a follow-up PR.

## (Optional) Issue link

olive/cli/base.py

@@ -481,6 +481,7 @@ def add_dataset_options(sub_parser, required=True, include_train=True, include_e
         type=unescaped_str,
         help=r"Template to generate text field from. E.g. '### Question: {prompt} \n### Answer: {response}'",
     )
+    text_group.add_argument("--use_chat_template", action="store_true", help="Use chat template for text field.")
     dataset_group.add_argument(
         "--max_seq_len",
         type=int,
@@ -526,6 +527,7 @@ def update_dataset_options(args, config):
         ),
         ((*preprocess_key, "text_cols"), args.text_field),
         ((*preprocess_key, "text_template"), args.text_template),
+        ((*preprocess_key, "chat_template"), args.use_chat_template),
         ((*preprocess_key, "max_seq_len"), args.max_seq_len),
         ((*preprocess_key, "add_special_tokens"), args.add_special_tokens),
         ((*preprocess_key, "max_samples"), args.max_samples),