[NFR] Forms should also have attributes

[scrnjakovic]

I suggest implementing attributes collection for Phalcon\Forms\Form. Like other HTML tags/elements, <form> has attributes as well so I don't see why we shouldn't support that?

$form->setAttribute('data-field', 'myValue');

How would we use it?
I know there is a difference between elements and the form as you render elements with the help of the form and you render form with the help of the Phalcon\Tag but it would still be helpful to be able to set attributes outside of the view.

{{  form('action', myForm.getAttributes()) }}
{# or #}
{{  form(myForm) }}
{# or #}
{{ myForm.renderSelf() }}

[niden]

Closing in favor of #13855. Will revisit if the community votes for it, or in later versions.

[niden]

cc @emiliodeg

[niden]

Resolved in #14082