URL Params do not work as expected for flag type params

`get_param("reverse")` does not return `Some("")` as expected for query string `?reverse`
The expected behavior for URLParams is to treat params with no `=` in them as if the same as an empty value
`localhost:80/api/users?reverse` should be equivalent to `localhost:80/api/users?reverse=`

reference:
https://developer.mozilla.org/en-US/docs/Web/API/URLSearchParams#empty_value_vs._no_value