The attachment gallery picker is not preserving image ratio when downscaling

Reproduction steps:

• upload the 3 images in attachment of this issue on a page (200_200, 200_100, 100_200)
• edit the page and open the gallery picker in the image selection

Expected:

Actual:

Proposed fix, add keepAspectRatio=true to the image urls https://github.com/xwiki/xwiki-platform/blob/1eed1c849aa852824e8e3f4961fcc472e4e8992d/xwiki-platform-core/xwiki-platform-attachment/xwiki-platform-attachment-picker/xwiki-platform-attachment-picker-webjar/src/main/webjar/attachmentGalleryPicker.js#L249