Request.formData() doesn't support application/x-www-form-urlencoded

[brophdawg11]

Per the spec the Request.formData should support parsing body of Content-Type: application/x-www-form-urlencoded, but it currently only supports multipart/form-data. I have an update locally and can open a PR shortly

[brophdawg11]

Here's a quick JS snippet to show the expected behavior:

(async () => {
    let searchParams = new URLSearchParams();
    searchParams.append('key', 'value');
    let request = new Request('/', { 
        method: 'POST', 
        headers: { 'Content-Type': 'application/x-www-form-urlencoded' }, 
        body: searchParams,
    })
    let requestFormData = await request.formData();
    console.log('key =', requestFormData.get('key'));
})()