💄(frontend) change icon duplicate feature

We change the icon for the duplicate feature
in the document toolbox and the documents grid
actions from 'call_split' to 'content_copy'
to better reflect the action of duplicating a
document.

src/frontend/apps/impress/src/features/docs/doc-header/components/DocToolBox.tsx

@@ -164,7 +164,7 @@ export const DocToolBox = ({ doc }: DocToolBoxProps) => {
     },
     {
       label: t('Duplicate'),
-      icon: 'call_split',
+      icon: 'content_copy',
       disabled: !doc.abilities.duplicate,
       callback: () => {
         duplicateDoc({

src/frontend/apps/impress/src/features/docs/docs-grid/components/DocsGridActions.tsx

@@ -72,7 +72,7 @@ export const DocsGridActions = ({
     },
     {
       label: t('Duplicate'),
-      icon: 'call_split',
+      icon: 'content_copy',
       disabled: !doc.abilities.duplicate,
       callback: () => {
         duplicateDoc({