fix: Multiple UI/UX improvements (#2529)

This includes multiple improvements described in https://github.com/openedx/frontend-app-authoring/issues/2528

src/course-unit/preview-changes/index.tsx

@@ -4,7 +4,7 @@ import {
 import {
   ActionRow, Button, Icon, ModalDialog, useToggle,
 } from '@openedx/paragon';
-import { Info, Warning } from '@openedx/paragon/icons';
+import { Info } from '@openedx/paragon/icons';
 import { useIntl, FormattedMessage } from '@edx/frontend-platform/i18n';
 
 import { ToastContext } from '@src/generic/toast-context';
@@ -150,7 +150,7 @@ export const PreviewLibraryXBlockChanges = ({
     return (
       <CompareChangesWidget
         usageKey={blockData.upstreamBlockId}
-        oldUsageKey={isTextWithLocalChanges ? blockData.downstreamBlockId : undefined}
+        oldUsageKey={blockData.downstreamBlockId}
         oldTitle={isTextWithLocalChanges ? blockData.displayName : undefined}
         oldVersion={blockData.upstreamBlockVersionSynced || 'published'}
         newVersion="published"
@@ -235,21 +235,14 @@ export const PreviewLibraryXBlockChanges = ({
         </ModalDialog.Title>
       </ModalDialog.Header>
       <ModalDialog.Body>
-        {isTextWithLocalChanges ? (
+        {isTextWithLocalChanges && (
           <AlertMessage
             show
             variant="info"
             icon={Info}
             title={intl.formatMessage(messages.localEditsAlert)}
           />
-        ) : (!blockData.isContainer && (
-          <AlertMessage
-            show
-            variant="warning"
-            icon={Warning}
-            title={intl.formatMessage(messages.olderVersionPreviewAlert)}
-          />
-        ))}
+        )}
         {getBody()}
       </ModalDialog.Body>
       <ModalDialog.Footer>

src/course-unit/preview-changes/messages.ts

@@ -51,11 +51,6 @@ const messages = defineMessages({
     defaultMessage: 'Ignore',
     description: 'Preview changes confirmation dialog confirm button text when user clicks on ignore changes.',
   },
-  olderVersionPreviewAlert: {
-    id: 'course-authoring.review-tab.preview.old-version-alert',
-    defaultMessage: 'The old version preview is the previous library version',
-    description: 'Alert message stating that older version in preview is of library block',
-  },
   localEditsAlert: {
     id: 'course-authoring.review-tab.preview.loal-edits-alert',
     defaultMessage: 'This library content has local edits.',
@@ -73,7 +68,7 @@ const messages = defineMessages({
   },
   updateToPublishedLibraryContentBody: {
     id: 'course-authoring.review-tab.preview.update-to-published.modal.body',
-    defaultMessage: 'Updating this block will discard local changes. Any eidts made within this course will be discarted, and cannot be recovered',
+    defaultMessage: 'Updating this block will discard local changes. Any edits made within this course will be discarded, and cannot be recovered',
     description: 'Body of the modal to update a content to the published library content',
   },
   updateToPublishedLibraryContentConfirm: {
@@ -93,7 +88,7 @@ const messages = defineMessages({
   },
   keepCourseContentBody: {
     id: 'course-authoring.review-tab.preview.keep-course-content.modal.body',
-    defaultMessage: 'This will keep the locally edited course content. if the component is published again in its library, you can choose to update to published library content',
+    defaultMessage: 'This will keep the locally edited course content. If the component is published again in its library, you can choose to update to published library content',
     description: 'Body of the modal to keep the content of a course component',
   },
 });