fix(ie/edge): form.method='delete', raises Invalid argument.

[mfo]

IE issue (edge) : FormElement.method attribute only accepts "get|post". To my surprise, it seems to be the expected behaviour from the spec: https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#form-submission-attributes. TLDR ;

The method and formmethod content attributes are [enumerated attributes](https://html.spec.whatwg.org/multipage/common-microsyntaxes.html#enumerated-attribute) with the following keywords and states:
    The keyword get, mapping to the state GET, indicating the HTTP GET method.
    The keyword post, mapping to the state POST, indicating the HTTP POST method.
    The keyword dialog, mapping to the state dialog, indicating that submitting the [form](https://html.spec.whatwg.org/multipage/forms.html#the-form-element) is intended to close the [dialog](https://html.spec.whatwg.org/multipage/interactive-elements.html#the-dialog-element) box in which the form finds itself, if any, and otherwise not submit.

So when the form.method attribute is not get or post IE/edge raises an Invalid argument error. How to reproduce: open ie edge console : document.createElement('form').method="delete" > raise Invalid arg
At first, to avoid this issue, we I went the rails way creating an <input type="hidden" value="{linkMethod}" name="_method" /> appended to the "virtual" form. But tchak is right ; form.setAttribute('method') make it works

[tchak]

An alternative (and less framework dependent) implementation would be to replace form.method with form.setAttribute('method'). The actuall request is done by fetch/xhr anyway so it will work. But using setAttribute would prevent some browsers from crashing.

[dhh]

Please strip ; as we don't use those in our linter. Thanks!

[mfo]

Please strip ; as we don't use those in our linter. Thanks!

done. thanks for the review and turbo.