Parse permit URL

Right now [here](https://github.com/ubiquity/ubiquibot/blob/aeb5956cfdbbb0d05942f2aa3c0eb5e4126eea09/src/handlers/payout/action.ts#L149) we use a plain string comparison to check that the comment is a permit URL. This approach is brittle.

We should parse URL with [URLSearchParams](https://developer.mozilla.org/en-US/docs/Web/API/URLSearchParams) in order to not rely on query parameters order.