`footer` element test

Pass Criteria

#1: Element is supported
#2: Correct HTML and Core Accessibility API mappings
#3: Correct Accessible Name & Description Calculation

Reference

Test ft-001: `footer` element, sectioning content/root is `body`

footer element

Test ft-002: `footer` element, sectioning content/root is not `body`

footer element inside article

Test ft-003: `footer` with `aria-label`

Test ft-004: `footer` with `aria-labelledby`

Test ft-005: `footer` with `title` attribute.

Test ft-006: `footer` with `aria-describedby`

Test ft-007: `footer` with `aria-label` & `title` attributes