Merge branch 'master' into feature/schemer

# Conflicts:
#	projects/common/models/elements/compound-elements/cloze/cloze-child-elements/drop-list-simple.ts
#	projects/common/models/elements/compound-elements/cloze/cloze-child-elements/text-field-simple.ts
#	projects/common/models/elements/compound-elements/cloze/cloze-child-elements/toggle-button.ts
#	projects/common/models/elements/compound-elements/likert/likert-row.ts
#	projects/common/models/elements/element.ts
#	projects/common/models/elements/input-elements/checkbox.ts
#	projects/common/models/elements/input-elements/drop-list.ts
#	projects/common/models/elements/input-elements/dropdown.ts
#	projects/common/models/elements/input-elements/radio-button-group-complex.ts
#	projects/common/models/elements/input-elements/radio-button-group.ts
#	projects/common/models/elements/input-elements/slider.ts
#	projects/common/models/elements/input-elements/spell-correct.ts
#	projects/common/models/elements/input-elements/text-area.ts
#	projects/common/models/elements/input-elements/text-field.ts
#	projects/common/models/elements/text/text.ts
#	projects/common/models/section.ts
#	projects/editor/src/app/services/verona-api.service.ts