Fix some UI inconsistencies #122

Describe the bug
There are now some inconsistencies in the design system. These mostly regards the theme, size, padding, margins, etc.
A lot of sizes are also not used and some semantic elements are used wrong. Things can also be compacted a bit and the typography simplified.
Also some better CSS resets can be globalized such as border-box.
Also some names of prompts are not consistent such as hasError and error for showing error states in components.