FEAT #11641 TIME 2 add handle empty folder + add var lang

src/frontend/app/actions/actions-list.component.html

src/frontend/app/actions/actions-list.component.ts

...lder/folder-action-list/folder-action-list.component.html

...rontend/app/folder/folder-menu/folder-menu.component.html

...rontend/app/folder/folder-menu/folder-menu.component.scss

src/frontend/app/folder/folder-menu/folder-menu.component.ts

src/frontend/app/folder/folder-tree.component.html

src/frontend/app/folder/folder-tree.component.scss

src/frontend/lang/lang-en.ts

src/frontend/lang/lang-fr.ts

src/frontend/lang/lang-nl.ts

src/frontend/plugins/sorting.pipe.ts