Add Data Type icon to column listings

[jthi]

Add Data Type icon, similarly as Modeling Type already is, to column listings. Most likely best to add as new preference option in Tables menu if some people want to keep old behaviour (but enable by default as it would already help solving issues in Community :)). This should be extended to all column listings which already have Modeling Type visible.

Example with Character and Numeric columns (of course JMP has few more)

Also quick option to change datatype could be nice, but I guess this could cause issues.

[SamGardner]

This is being investigated along with this more recent request. More icons to column listing