MC-5232: Prefix field names with section name to avoid field name collision

- Remove testing dot notation for layout
- Resolve issue with background images converter

Author: davemacaulay

app/code/Magento/PageBuilder/view/adminhtml/pagebuilder/content_type/row.xml

@@ -47,7 +47,7 @@
                             <style name="border_width" source="border_width" converter="Magento_PageBuilder/js/converter/style/remove-px"/>
                             <style name="border_radius" source="border_radius" converter="Magento_PageBuilder/js/converter/style/remove-px"/>
                             <style name="justify_content" source="justify_content" persistence_mode="read"/>
-                            <style name="layout.min_height" source="min_height" converter="Magento_PageBuilder/js/converter/style/remove-px"/>
+                            <style name="min_height" source="min_height" converter="Magento_PageBuilder/js/converter/style/remove-px"/>
                             <style name="margins" storage_key="margins_and_padding" reader="Magento_PageBuilder/js/property/margins" converter="Magento_PageBuilder/js/converter/style/margins" preview_converter="Magento_PageBuilder/js/content-type/row/converter/style/margins"/>
                             <style name="padding" storage_key="margins_and_padding" reader="Magento_PageBuilder/js/property/paddings" converter="Magento_PageBuilder/js/converter/style/paddings" preview_converter="Magento_PageBuilder/js/content-type/row/converter/style/paddings"/>
                             <attribute name="enable_parallax" source="data-enable-parallax"/>

app/code/Magento/PageBuilder/view/adminhtml/web/js/mass-converter/background-images.js

@@ -20,13 +20,11 @@ export default class BackgroundImages implements ConverterInterface {
     public fromDom(data: ConverterDataInterface, config: ConverterConfigInterface): ConverterDataInterface {
         const directive = get<string>(data, config.attribute_name);
         if (directive) {
-            const desktopImage = get<ImageArrayObject>(data, config.desktop_image_variable);
-            const mobileImage = get<ImageArrayObject>(data, config.mobile_image_variable);
             const images = JSON.parse(directive.replace(/\\(.)/mg, "$1")) || {};
-            if (!_.isUndefined(desktopImage)) {
+            if (!_.isUndefined(images.desktop_image)) {
                 set(data, config.desktop_image_variable, decodeUrl(images.desktop_image));
             }
-            if (!_.isUndefined(mobileImage)) {
+            if (!_.isUndefined(images.mobile_image)) {
                 set(data, config.mobile_image_variable, decodeUrl(images.mobile_image));
             }
             delete data[config.attribute_name];