[editor] Fix IDs of duplicated elements

...s/common/models/elements/compound-elements/cloze/cloze.ts

...common/models/elements/compound-elements/likert/likert.ts

...s/common/models/elements/compound-elements/table/table.ts

projects/common/models/elements/element.ts

projects/common/models/elements/input-elements/drop-list.ts

projects/common/models/page.ts

projects/common/models/section.ts

...pp/components/unit-view/section/section-menu.component.ts

.../editor/src/app/services/unit-services/element.service.ts

.../editor/src/app/services/unit-services/section.service.ts

...t-editor/angular-node-views/button-component-extension.ts

...editor/angular-node-views/checkbox-component-extension.ts

...ditor/angular-node-views/drop-list-component-extension.ts

...itor/angular-node-views/text-field-component-extension.ts

...r/angular-node-views/toggle-button-component-extension.ts