simplify internal UI table state management

[heswell]

we are jumping through some hoops at the moment to maintain the correct state in tableConfig within vuu-table. We can simplify logic by simply making tableConfig a controlled prop. It can be controlled/uncontrolled at the Table level and controlled at the inner TableCore level.
This can be seen in the code that currently sets column widths on tableConfig .

Need to be careful, many operations update tableConfig. We want to avoid unnecesary renders.