fix(search) : set scroll bar to list structures + fix test

src/app/app.component.scss

src/app/footer/footer.component.scss

src/app/header/header.component.scss

src/app/home/home.component.html

src/app/home/home.component.scss

...structure-list/components/search/search.component.spec.ts

src/app/structure-list/structure-list.component.html

src/app/structure-list/structure-list.component.scss