Move all the markup of the `FormCheckBox` class into the template file
Rework the `FormTextField` and `FormTextArea` widgets
Rework the `FormSubmit` widget and mark the deprecated methods
Rework the `FormSelectMenu` widget
Rework the `FormRadioButton` widget
Rework the `FormPassword` widget
Rework the `FormHtml` widget
Rework the `FormHidden` widget
Rework the `FormHeadline` and `FormExplanation` widgets
Rework the `FormFileUpload` widget
Rework the `FormFieldset` widget
Rework the `FormCaptcha` widget
Fine-tune the changed resources
Add a change log entry
Merge branch 'feature/form-field-rework' into develop