This commit adds a check that runs regularly as per
2d68e5d942 which tests the
credentials of groups with SMTP or IMAP enabled. If any issues
are found with those credentials a high priority problem is added to the
admin dashboard.
This commit also formats the admin dashboard differently if
there are high priority problems, bringing them to the top of
the list and highlighting them.
The problem will be cleared if the issue is fixed before the next
problem check, or if the group's settings are updated with a valid
credential.
A first step to adding automatic dark mode color scheme switching. Adds a new SCSS file at `color_definitions.scss` that serves to output all SCSS color variables as CSS custom properties. And replaces all SCSS color variables with the new CSS custom properties throughout the stylesheets.
This is an alpha feature at this point, can only be enabled via console using the `default_dark_mode_color_scheme_id` site setting.
