[FEATURE] Add ability to specify dataset problem type during data import

[MartinBarus]

🚀 Feature

LLM studio supports multiple problem types (Causal Modeling/ Classification), however, during data import, it expects dataset to be named exactly as the problem type, otherwise proper problem type can not be set.

Motivation

When importing custom dataset named train.csv for classification, it would be great to have the ability to select proper problem type.

[MartinBarus]

Maybe add this snippet

items += [
                ui.dropdown(
                    name="dataset/import/cfg_file",
                    label="Problem Type",
                    required=True,
                    choices=choices_problem_types,
                    value=q.client["dataset/import/cfg_file"],
                    trigger=True,
                    tooltip=tooltips["experiments_problem_type"],
                )
            ]

here :https://github.com/h2oai/h2o-llmstudio/blob/d1acb59/llm_studio/app_utils/sections/dataset.py#L491