Switch invalid styles

[rkaraivanov]

Currently an invalid igc-switch has no visual indication informing the end-user about its state.

One can set the --error-color CSS variable and then the component will use that as the base of styling its invalid state. However, this is mentioned neither in the official documentation nor in the specification for the component. It is in stark contrast to the igc-checkbox component which comes with default styling for its invalid state.

Also, while most form associated components apply the required styles for their label (the * suffix), the switch and checkbox don't.

Can you confirm these behaviors are by design and if so, create issues to update the relevant documentation and samples? Otherwise, set some uniform base requirements how they should look/behave so we can proceed to update the components according to those requirements.