update radio field to use correct b4 classes for validation

[calebsyring]

May fix #156 for the b4 template. Not meant to make a final decision on it. It was necessary to stop using label/input shorthand to get the bootstrap validation styling to work:

Due to constraints in how CSS works, we cannot (at present) apply styles to a <label> that comes before a form control in the DOM without the help of custom JavaScript.

https://getbootstrap.com/docs/4.6/components/forms/#how-it-works

[codecov]

Codecov Report

Merging #159 (ff0dd18) into master (69003d3) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #159   +/-   ##
=======================================
  Coverage   95.95%   95.95%           
=======================================
  Files          33       33           
  Lines        3385     3385           
=======================================
  Hits         3248     3248           
  Misses        137      137           

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[guruofgentoo]

Incorporated these changes separately.