feat: input adorners for number and text fields

[Skaiir]

Closes #420

[pinussilvestrus]

This reads a bit redundant. Should we have the schema like this?

{
  type: 'number',
  adorners: {
    prefix: '',
    suffix: ''
  }
}

[pinussilvestrus]

or, as basically proposed by @christian-konrad

{
  type: 'number',
  display: {
    prefixAdorner: '',
    suffixAdorner: ''
  }
}

[pinussilvestrus]

It's now

{
  type: 'number',
  appearance: {
    prefixAdorner: '',
    suffixAdorner: ''
  }
}

[pinussilvestrus]

I added some more test coverage. Looks good to me, nice little improvement 👍