8359024: Accessibility bugs in API documentation

[hns]

Please review a change to fix a couple of accessibility errors in JDK API documentation as detected by our accessibility testing.

• Contrast between link and normal text colors was below 3 and therefore would have required other styling (such as underlining). This is fixed by slightly darkening text color (our text color isn't black but dark-gray).
  Old colors: https://webaim.org/resources/linkcontrastchecker/?fcolor=282828&bcolor=FFFFFF&lcolor=437291
  New colors: https://webaim.org/resources/linkcontrastchecker/?fcolor=181818&bcolor=FFFFFF&lcolor=437291

• Links in the headings of inherited member summaries used the wrong color and contrast to background color was below 4.5. This is fixed by removing a bogus .expanded selector that shouldn't have been there in the first place.
  Old colors: https://webaim.org/resources/linkcontrastchecker/?fcolor=181818&bcolor=DEE3E9&lcolor=437291
  New colors: https://webaim.org/resources/linkcontrastchecker/?fcolor=181818&bcolor=DEE3E9&lcolor=47688A

• Remove the role="tablist" and aria-orientation="horizontal" attributes from table captions if they do not contain tabs. This is the only code change, and the only change that comes with a test change (I guess the CSS changes are noreg-hard as we don't have a way to do automatic accessibility testing).

All changes are invisible or so subtle that they are practically impossible to spot in normal browsing, so I spare myself the task of uploading demo docs.

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Progress

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Issue

• JDK-8359024: Accessibility bugs in API documentation (Bug - P3)

Reviewers

• Volkan Yazici (@vy - Committer)

Reviewing

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