General radio choosing
General radio choosing

Create common functions, similar to the checkbox ones, for
finding all radios and for choosing radio buttons, making
sure they are visible before they are chosen.

Not sure if more refactoring would be helpful, but this seemed
like a reasonable place for me to stop.

alphagov/digitalmarketplace-functional-tests,alphagov/digitalmarketplace-functional-tests,alphagov/digitalmarketplace-functional-tests