Add autofocus to inputfield  when asking a question

Closes #422

See merge request arsnova/frag.jetzt!419

change slider style

Closes #419

See merge request arsnova/frag.jetzt!416

Merge branch '418-questions-with-an-answer-are-displayed-distorted-in-the-roles-of-student-and-moderator' into 'master'

resolve undefined id for comment component

Closes #418

See merge request arsnova/frag.jetzt!415

set questionwall initial font size to 200

Closes #417

See merge request arsnova/frag.jetzt!414

Merge branch '409-clicking-on-a-question-should-open-the-answer-view-without-switching-to-full-view' into 'master'

deactivate fullscreen for question expand

Closes #409

See merge request arsnova/frag.jetzt!413

Merge branch '411-question-focus-increase-the-default-text-size-to-200-and-display-the-text-scaling-slider' into 'master'

add slider to questionwall

Closes #411

See merge request arsnova/frag.jetzt!412