custom logo for district pages

...ations/0299_districthomepage_custom_logo_dark_and_more.py

...0300_remove_districthomepage_custom_logo_dark_and_more.py

district/models.py

district/templates/district/district_home_page.html

shared/models/main.py

...tyleguide2/includes/organisms/layout/district/navbar.html

...igrations/0113_alter_uniwebhomepage_dark_logo_and_more.py

uniweb/models.py