HtmlTag does not support additional properties

[cmacioch]

The HtmlTag should have support for additional properties.
It should be possible to produce the following XML using the HtmlTag annotation:

    <cq:htmlTag jcr:primaryType="nt:unstructured"
                cq:tagName="nav"
                class="component breadcrumb"
                aria-label="Breadcrumb"
                additionalAttributeName="additionalAttributeValue"/>

The above XML is valid and it results in adding all of the non-standard attributes to the component decoration tag.
Adobe documentation mentions that properties other than 'cq:tagName' and 'class' will be added as HTML attributes with the same String value as provided.
https://helpx.adobe.com/experience-manager/6-4/sites/developing/using/decoration-tag.html