Revert "Fieldset and legend solution is lost when edit Problem"

common/lib/capa/capa/capa_problem.py

common/lib/capa/capa/inputtypes.py

common/lib/capa/capa/templates/choicegroup.html

common/lib/capa/capa/tests/test_html_render.py

common/lib/capa/capa/tests/test_input_templates.py

common/lib/capa/capa/tests/test_inputtypes.py

common/lib/xmodule/xmodule/js/spec/problem/edit_spec.coffee

common/lib/xmodule/xmodule/js/src/problem/edit.coffee

...module/xmodule/templates/problem/checkboxes_response.yaml

...lib/xmodule/xmodule/templates/problem/multiplechoice.yaml

.../xmodule/xmodule/templates/problem/numericalresponse.yaml

...lib/xmodule/xmodule/templates/problem/optionresponse.yaml

...ib/xmodule/xmodule/templates/problem/string_response.yaml