feat: updates functions and how they are rendered

[mosmuell]

Changes:

• (breaking) functions that are rendered in the frontend cannot take arguments any more! Synchronous functions are rendered as buttons with a display name defined by either the function name of the displayName set in the web_settings.json file.
• removes card header of root component
• changes react component file structure (updates Adding_Components.md file accordingly)
• serialization of methods has changes
  • replaces "parameters" with "signature" -> contains both parameters and return annotation
• updates Readme