FEAT #14454 TIME 1:45 fix css + add header option + fix delimiter options + fix var lang

...pp/administration/user/import/users-import.component.html

.../app/administration/user/import/users-import.component.ts

...p/administration/user/users-administration.component.html

src/frontend/service/debug/dev-lang.component.html

src/lang/lang-en.json

src/lang/lang-fr.json

src/lang/lang-nl.json