Replace jQuery validate in book/author/tag edit forms

[rebecca-shoptaw]

Subtask of #9605.

Feature. Replaces jQuery validate required field and email validation with built-in HTML validation to improve performance, JS-disabled functionality, and internationalization.

Technical

Quite simple! Just removed the validate class (which triggers the plugin), and replaced each class="required" with the HTML required attribute and each class="email" with the HTML type="email" attribute.

Testing

1. Go to one of the relevant forms, i.e. a book edit form
2. Enter a badly formatted email and/or leave a required field blank, hit submit
3. The submission should fail and you should see an HTML-native error message

Screenshot

Stakeholders

@cdrini

[jimchamp]

Thanks @rebecca-shoptaw! Turns out the the Tag validations weren't even working, so this is a great help.