Use Bulma helpers whenever possible instead of custom styled components.
This pull request replaces primarily color definitions, spacing and flex instructions.
In the release of version 2.0.0 of SCM-Manager, the health checks had been neglected. This makes them visible again in the frontend and adds the ability to trigger them. In addition there are two types of health checks: The "normal" ones, now called "light checks", that are run on startup, and more intense checks run only on request.
As a change to version 1.x, health checks will no longer be persisted for repositories.
Co-authored-by: Eduard Heimbuch <eduard.heimbuch@cloudogu.com>