lint: forbid comma separated selectors in selectors

[layershifter]

We need add a ESLint rule that will forbid :hover,:active selectors.

makeStyles({
  root: {
     // 🟢 should pass
    ":hover": { color: "red" },
    ":active": { color: "blue" },
    // 🔴 should break
    ":hover,:active": { color: "blue" },
  },
});

For context, #495.

[NotWoods]

Possibly as an option, I think it would be helpful to allow comma-separated selectors only if they all include &.

makeStyles({
  root: {
     // 🟢 should pass
    "&:hover, &:active": { color: "blue" },
    // 🔴 should break
    ":hover,&:active": { color: "blue" },
  },
});