Fix submitting TagDiscussionModal via enter key
Fix submitting TagDiscussionModal via enter key

The DOM submit method doesn't raise a `submit` event (https://developer.mozilla.org/en-US/docs/Web/API/HTMLFormElement/submit), so submitting the form this way just refreshed the page (default HTML form behavior). The recommended fix (and the one implemented here) is to simulate a button-triggered submission.

Fixes https://github.com/flarum/core/issues/2595

flarum/tags,flarum/tags,flarum/tags