fix(ui-library): does not show icons when undefined

[DenizSaganak]

Ticket HintIcon & errorIcon can not be hidden/undefined anymore for multiple form components#625

[davidken91]

It looks like the compile step is failing. I think you just need to add icons as a property to contentIconButtons index.stories.ts (button group). Something like this:
const contentIconButtons = html
${BlrIconButtonRenderFunction({
size: 'md',
theme: 'Light',
loading: false,
variant: 'primary',
loadingStatus: 'Loading',
disabled: false,
arialabel: 'button_1',
icon: 'blr360'
})}
${BlrIconButtonRenderFunction({
size: 'md',
theme: 'Light',
loading: false,
variant: 'secondary',
loadingStatus: 'Loading',
disabled: false,
arialabel: 'button_2',
icon: 'blrInfo'
})}
;