fix: Bug when adding spaces to containers names in course outline (#2825)

- Fixes the bug introduced in https://github.com/openedx/frontend-app-authoring/pull/2732
- Removes the unnecessary `preventDefault`

src/course-outline/card-header/CardHeader.tsx

@@ -178,9 +178,14 @@ const CardHeader = ({
               onChange={(e) => setTitleValue(e.target.value)}
               aria-label={intl.formatMessage(messages.editFieldAriaLabel)}
               onBlur={() => onEditSubmit(titleValue)}
-              onKeyDown={(e) => {
+              onKeyDown={/* istanbul ignore next */ (e) => {
                 if (e.key === 'Enter') {
                   onEditSubmit(titleValue);
+                } else if (e.key === ' ') {
+                  // Avoid passing propagation to the `SortableItem` in the card,
+                  // which executes a `preventDefault`. If propagation is not prevented,
+                  // spaces cannot be added to names.
+                  e.stopPropagation();
                 }
               }}
               disabled={isSaving}