Add column support to text body properties

[awdorrin]

Issue Category

• [x] Enhancement
• [ ] Bug
• [ ] Question
• [ ] Documentation gap/issue

Product Versions

• Please specify what version of the library you are using......: [ 3.12.0 ]
• Please specify what version(s) of PowerPoint you are targeting: [ 16 ]
• Please specify what web browser you are using.................: [ Chrome/FireFox/Edge ]

Desired Behavior

In PowerPoint, with a text box selected, you can choose the number of columns (2, 3 or more) This sets the bodyPr tag as follows:

                <p:txBody>
                    <a:bodyPr wrap="square" numCol="2" rtlCol="0" anchor="t">
                        <a:normAutofit/>
                    </a:bodyPr>

It would be useful to be able set this, even if only works like fit: "shrink" where a manual edit in the resulting powerpoint is needed to recalculate.