Completes the contract added to the rest of the form controls in 1.32.0.
Both u-radio and u-rating are option/symbol groups rather than a single
target, so .focus() delegates to the first option (u-radio) or the first
symbol (u-rating) regardless of the current selection, and .blur() blurs
whichever option/symbol currently holds focus (roving tabindex may have
moved it away from the first one).

Bump to 1.33.0 (additive, no breaking change).