Remove public "standard_pages" app (#3721)

docs/getting-started/architecture.md

hypha/public/forms/models.py

hypha/public/funds/models.py

hypha/public/navigation/models.py

...a/public/navigation/templates/navigation/breadcrumbs.html

hypha/public/news/models.py

hypha/public/partner/models.py

hypha/public/people/models.py

...ions/0009_remove_informationpage_header_image_and_more.py

hypha/public/standardpages/models.py

...lic/standardpages/templates/standardpages/index_page.html

...andardpages/templates/standardpages/information_page.html

hypha/public/utils/blocks.py

hypha/public/utils/models.py

hypha/static_src/src/sass/public/components/_nav.scss

hypha/templates/base.html

public/sandbox_db.dump