Styling (& refactoring) for further screens

[JohannSiemens]

This is basically a clone of US8 to implement further styling throughout the rest of the application. The previous US got too big in terms of lines of code, so i had to split the user story.

Value proposition:

As a developer i want my application to have a uniformly and appealing styling throughout every component to be able to fulfill the user requirements in terms of visualization.

As a user i want the application i use to look appealing to me and fulfill the requirements to a certain user experience standard to be able to use the application frequently and intuitively.

Acceptance criteria:

• [ ] The application should be accessible
• [x] The styling should be uniformly (e.g. colors, generell styling concept)
• [x] The design should take the user experience and workflows into account
• [x] All features should still work, as they did before the styling

Tasks:

• [x] Create branch
• [ ] Write tests
• [x] Implement the styled components for the further screens (the exercises overview within the workout)
• [x] Refactor the "card component" for the workouts overview into a "form" (edit mode) and a "section" (display mode) within the list-item

[JohannSiemens]

PR & QA for the refactoring of the workout-card component is done and merged!

[JohannSiemens]

QA done and merged successfully!