Add comments for search multiple module => DONE

...ch-multiple/components/datasets/dataset-list.component.ts

...tiple/components/datasets/datasets-by-family.component.ts

...ch-multiple/components/progress-bar-multiple.component.ts

...h-multiple/components/result/datasets-result.component.ts

...-multiple/components/result/download-section.component.ts

...p/search-multiple/components/result/overview.component.ts

.../search-multiple/components/summary-multiple.component.ts

src/app/search-multiple/containers/datasets.component.ts

src/app/search-multiple/containers/position.component.ts

...p/search-multiple/containers/result-multiple.component.ts

...p/search-multiple/containers/search-multiple.component.ts

src/app/search-multiple/search-multiple-routing.module.ts

src/app/search-multiple/search-multiple.module.ts

src/app/search-multiple/store/model/data-by-dataset.model.ts

src/app/search-multiple/store/model/dataset-count.model.ts

...ultiple/store/model/search-multiple-query-params.model.ts

src/app/search-multiple/store/search-multiple.action.ts

src/app/search-multiple/store/search-multiple.effects.ts

src/app/search-multiple/store/search-multiple.reducer.ts

src/app/search-multiple/store/search-multiple.service.ts