Add/Improve readonly styles

[rin]

I added some read only styles to input and labeled input, but they can probably be improved. We should also add them to the other HTML form elements:

• [ ] select
• [ ] radio button
• [ ] text area
• [ ] potentially … phone input?

I think checkbox is not needed …?

[rin]

@lulen11 Happy for you to jump onto this whenever you are … bored 😅