fix(access-name): get name from header elements

[WilcoFiers]

The content of landmarks and other elements that have "name from author" should not be ignored when referenced by aria-labelledby or another label.

This is a bug, where axe was inconsistent with the accessible name spec. Specifically, step F:

if the current node's role allows name from content, or if the current node is referenced by aria-labelledby, aria-describedby, or is a native host language text alternative element (e.g. label in HTML), or is a descendant of a native host language text alternative element

Previously axe-core was only considering the first part of this sentence, and skipping name from author elements while following aria-labelledby and <label> IDREFs. This was a problem on dialogs (as the issue reported), but had broader implications too. Notably, column and rowheaders in a table could not be referenced with aria-labelledby.

That created a second problem; Elements with a value (like select and progressbar) should never use name from content. I had to add a condition in for that. I ended up testing the use of element values in names again. This improved a good bit, and so now only the value of progressbar still can't be relied on to give an accessible name.

Closes: #3752

[WilcoFiers]

This label does nothing, and fail24 is not tested by this rule; this is not the select-name rule.

Done