Prevent skewing of resized images in editor (#2488)

* Unset inline size when shrinking images

to prevent skewing (https://forums.ankiweb.net/t/is-there-a-way-to-prevent-the-squish-skew-of-the-image-in-the-browser-editor/29925)

* Unset inline width/height for all images when shrinking is enabled

ts/editable/editable-base.scss

@@ -33,6 +33,9 @@ img:not(.mathjax) {
         :host-context(.shrink-image) & {
             max-width: var(--editor-default-max-width);
             max-height: var(--editor-default-max-height);
+            // prevent inline width/height from skewing aspect ratio
+            width: unset;
+            height: unset;
         }
     }