Add captions to user and space grid pages (#82713) (#83003)

* Add captions to user and space grid pages

* Address PR feedback: reword captions

* remove unused i18n values

Co-authored-by: Kibana Machine <42973632+kibanamachine@users.noreply.github.com>

Co-authored-by: Kibana Machine <42973632+kibanamachine@users.noreply.github.com>

x-pack/plugins/security/public/management/users/users_grid/users_grid_page.tsx

@@ -260,6 +260,10 @@ export class UsersGridPage extends Component<Props, State> {
             {
               <EuiInMemoryTable
                 itemId="username"
+                tableCaption={i18n.translate('xpack.security.management.users.tableCaption', {
+                  defaultMessage: 'Users',
+                })}
+                rowHeader="username"
                 columns={columns}
                 selection={selectionConfig}
                 pagination={pagination}

x-pack/plugins/spaces/public/management/spaces_grid/__snapshots__/spaces_grid_pages.test.tsx.snap

@@ -112,6 +112,7 @@ exports[`SpacesGridPage renders as expected 1`] = `
       }
       pagination={true}
       responsive={true}
+      rowHeader="name"
       search={
         Object {
           "box": Object {
@@ -120,6 +121,7 @@ exports[`SpacesGridPage renders as expected 1`] = `
         }
       }
       sorting={true}
+      tableCaption="Kibana spaces"
       tableLayout="fixed"
     />
   </EuiPageContent>

x-pack/plugins/spaces/public/management/spaces_grid/spaces_grid_page.tsx

@@ -110,6 +110,10 @@ export class SpacesGridPage extends Component<Props, State> {
         <EuiInMemoryTable
           itemId={'id'}
           items={this.state.spaces}
+          tableCaption={i18n.translate('xpack.spaces.management.spacesGridPage.tableCaption', {
+            defaultMessage: 'Kibana spaces',
+          })}
+          rowHeader="name"
           columns={this.getColumnConfig()}
           hasActions
           pagination={true}