Audited and updated roles source of truth to HTML Accessibility API Mapping 1.0

[jessebeach]

The W3C Working Draft of the HTML Accessibility API Mappings 1.0 is far enough along to use in an audit of this project's HTML to AX concept mapping.

In this Issue, we'll conduct an audit to determine what changes, if any, need to be made to match this spec: https://www.w3.org/TR/html-aam-1.0/

[coveralls]

Pull Request Test Coverage Report for Build 3615154072

• 8 of 8 (100.0%) changed or added relevant lines in 3 files are covered.
• 4 unchanged lines in 1 file lost coverage.
• Overall coverage decreased (-2.6%) to 95.455%

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Files with Coverage Reduction	New Missed Lines	%
src/elementRoleMap.js	4	80.39%

Totals
Change from base Build 3358745988:	-2.6%
Covered Lines:	248
Relevant Lines:	253

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💛 - Coveralls