added basic language selection page

metager/app/Localization.php

metager/config/laravellocalization.php

metager/lang/de/lang-selector.php

metager/lang/en/lang-selector.php

metager/resources/less/metager/pages/lang-selector.less

metager/resources/views/index.blade.php

metager/resources/views/lang-selector.blade.php

metager/resources/views/layouts/researchandtabs.blade.php

metager/resources/views/layouts/subPages.blade.php

metager/routes/web.php

metager/webpack.mix.js