Improve disabled Toggle appearance

[fbeceic]

Basic information

• Tiller version: 1.6.0
• Module: form-elements

Enhancement description

Improve the appearance of Toggle when the component is disabled.

Current behaviour

The component is currently only not responsive when it's disabled, but doesn't indicate so with its visual appearance. Other components have the opacity set to 50% when disabled, while this component doesn't.

Wanted behaviour

When disabled, the component should lower its opacity and indicate that it's disabled that way. The styles should be defined inside tokens though, in order to allow changing if needed.