Empty string array value not parsed correctly

[Shola Anozie]

Hi – first of all, thanks for your work on this library.

I ran into what I believe is a bug today and would like to understand if there is any way to work around it.

Given the following param definition:

const [urlParams, setUrlParams] = useQueryParams({
    foo: ArrayParam,
  });

Expected behaviour:

URL params	foo value
?foo=bar&foo=	['bar', '']
?foo=	['']

Actual behaviour:

URL params	foo value
?foo=bar&foo=	['bar', '']
?foo=	[]

[Shola Anozie]

It seems like the getEncodedValueArray function could be modified, although I might be blind to potential side effects:

function getEncodedValueArray(
  input: string | (string | null)[] | null | undefined
): (string | null)[] | null | undefined {
  if (input == null) {
    return input;
  }

  return input instanceof Array ? input : input === '' ? [''] : [input];  // Empty string no longer returns empty array
}