feat(pop-ups) - Allow to select an image for the pop-ups

src/API.ts

src/components/ImagePicker/ImagePicker.tsx

src/components/ImagePicker/SingleImage.tsx

src/components/ImagePicker/imagePicker.scss

src/components/Newsletter/MonthlyInfo/MonthlyInfo.tsx

src/components/Popups/Popups.tsx

src/components/SideBar/sidebar.scss

src/models/customPopup.model.ts

src/services/newsletter.service.ts

src/utils/imagesUrlsGetter.ts