Adding WCAG techniques as accessibility mappings (batch 2)

[Jym77]

Follow-up to #1014, handling some more rules.

Closes issue(s):

• Partially closes Map rules to WCAG techniques #1011 and Add techniques and WAI-ARIA as accessibility requirements #516.

Need for Final Call:
This will require a 1 week Final Call (small changes to accessibility mappings).

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[Jym77]

Final Call ends on February 6th.

[Jym77]

Final Call has ended. Merging.