Rethink Card Component

[nicosammito]

The card component currently has a lot of features and sub components that are completely unnecessary.
We should rather minimise the Card component to just a Card and a Card.Section component.

Card Component
The Card component should implement all colors and variants. Additionally we should add a gradient variant, which adds some coloured borders and a nice gradient background. Some images for that will follow.

Card.Section Component
The Card.Section component should simply erase the padding of the card component with a negative margin if withoutPadding is set to true. Also the Card.Section component should be able to add separators with borderTop and borderBottom.

This component is inspired by the Card component from mantine.

[nicosammito]

Here a sample image of a gradient card