Refactor: Use outline instead of ring

[thethunderturner]

Description

Closes #13733

Visual changes

none

Functional changes

• Code style has been fixed by running the composer cs command.
• Changes have been tested to not break existing functionality.
• Documentation is up-to-date.

[zepfietje]

Part of the migration from ring to outline should be using a consistent outline color.
Currently the primary color is used, which is an option, or we default to the browser's accent color as per the default behavior.

This improves current cases of the danger color being used for inputs with validation errors, which in hindsight is suboptimal.

[thethunderturner]

Part of the migration from ring to outline should be using a consistent outline color. Currently the primary color is used, which is an option, or we default to the browser's accent color as per the default behavior.

This improves current cases of the danger color being used for inputs with validation errors, which in hindsight is suboptimal.

Which one do we want to use? primary or browsers default? I think primary should work better because browsers could potentially have different default colors. Let me know if I misunderstood something!