Request for better "disabled" buttons

[venkr]

I think the following button style looks better for success when it is disabled:

const disabledSuccessStyle = {
        backgroundColor: theme.palette.successLight,
        borderColor: theme.palette.successLight,
        color: "#fff",
      }

I'm not sure I understand exactly how to put this into button/style.ts so would like you to drop this in when you get a chance! Temp workaround is applying these styles outside of sparkl-ui - but I'd like to remove that workaround when possible.

See a before/after comparison: