Introduce skipNullsInQueryString option

[pascalbaljet]

This PR introduces a skipNullsInQueryString visit option to exclude null values from the query string:

import { router } from '@inertiajs/react'

router.reload({ data: { foo: null } })

With the new option, it would make a request to / instead of /?foo. Still WIP because it misses tests, and I want to investigate if we could introduce a way to set this globally (same for queryStringArrayFormat).

[pascalbaljet]

Closing this one. If you want to exclude it from the query string, you should use undefined:

router.reload({ data: { foo: undefined } })