FEAT #11292 TIME 2 add var lang + add set admin in folder update + set parent folder

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

...end/app/folder/folder-update/folder-update.component.html

...ntend/app/folder/folder-update/folder-update.component.ts

src/frontend/lang/lang-en.ts

src/frontend/lang/lang-fr.ts

src/frontend/lang/lang-nl.ts