ARIA 1.3 Updates

[shunguoy]

This issue is for overall migration task for Aria 1.3. An individual issue should be opened as a sub-issue of this issue so they can all be categorized and organized.

• New roles: comment, suggestion, mark, image (synonym img), sectionheader, sectionfooter
• New attributes: aria-braillelabel, aria-brailleroledescription. The "aria-braillelabel" is prohibited whereever aria-label is prohibited
• Removed name required from author for the roles: alertdialog, dialog, form, grid, radiogroup and table.
• Presentational Role Inheritance: when an explicit or inherited role of none is applied to a native HTML element, all the allowed children have role 'none'.
• Clarify "generic" element in accessibility tree: user agents expose generic elements in accessibility APIs when permitted accessibility attributes have been specified. In contrast, in Aria 1.2, generic elements are exposed in accessibility APIs so that assistive technologies can gather certain properties such as layout and bounds
• Additional Roles with naming prohibited (should not use aria-label, aria-labelledby, or aria-braillelabel): definition, mark, term, time, tooltip
• Role "caption" can be used in group or radiogroup elements
• Allowed Accessibility Child Roles that allows but not requires a child, replacing Required Owned Elements.
• Required Accessibility Parent Role replaces Required Context Role. With clearer definition of Relationships in Accessibility Tree, including accessibility parent, accessibility children, and accessibility descendant.
• Role combobox is allowed to explicitly invoke menus
• The aria-hidden="false" synonyms to aria-hidden="undefined", cannot be used in document root (html, body).
• The aria-expanded is no longer required for listbox role.
• The aria-controls is no longer required for scrollbar role.
• The aria-details and aria-errormessage: accepts multiple IDs. An element can point to multiple distinct sections or documents providing deeper context