Updated all labels for Site header component and all components dependant of it.

src/components.d.ts

src/components/navigation/menu-item/menu-item.scss

src/components/navigation/menu-item/menu-item.tsx

src/components/navigation/menu-item/readme.md

src/components/navigation/menu-language/menu-language.scss

src/components/navigation/menu-language/menu-language.tsx

src/components/navigation/menu-language/readme.md

.../navigation/menu-level-container/menu-level-container.tsx

src/components/navigation/menu-level-container/readme.md

src/components/navigation/menu/menu.tsx

src/components/navigation/menu/readme.md

src/components/site-header/readme.md

src/components/site-header/site-header.tsx

src/components/site-header/site-search/readme.md

src/components/site-header/site-search/site-search.tsx