### Description

After the release for Airflow 2.6.0 I was integrating some forms into our setup and was missing some options selections - and some nice features to make selections user friendly.

I'd like do contribute some few features into the user forms:
* A select box option where proposals are made but user is not limited to hard `enum` list (`enum` is restricting user input to only the options provided)
* A multi-option pick list (because sometimes a single selection is just not enough
* Labels so that technical values used to control the DAG are different from what is presented as option to user

### Use case/motivation

After the initial release of UI trigger forms, add more features (incrementially)

### Related issues

Relates or potentially has a conflict with #31299, so this should be merged before.

### Are you willing to submit a PR?

- [X] Yes I am willing to submit a PR!

### Code of Conduct

- [X] I agree to follow this project's [Code of Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)

"x": 3,
        "text": "Hello World!",
        "flag": False,
        "a_simple_list": ["one", "two", "three", "actually one value is made per line"],
        
        
        
        "most_loved_number": Param(
            42,
            type="integer",
            title="You favorite number",
            description_html="""Everybody should have a favorite number. Not only math teachers.
            If you can not think of any at the moment please think of the 42 which is very famous because
            of the book
            <a href='https://en.wikipedia.org/wiki/Phrases_from_The_Hitchhiker%27s_Guide_to_the_Galaxy#
            The_Answer_to_the_Ultimate_Question_of_Life,_the_Universe,_and_Everything_is_42'>
            The Hitchhiker's Guide to the Galaxy</a>""",
        ),
        
        "pick_one": Param(
            "value 42",
            type="string",
            title="Select one Value",
            description="You can use JSON schema enum's to generate drop down selection boxes.",
            enum=[f"value {i}" for i in range(16, 64)],
        ),
        
        "bool": Param(