Revise pathname of article detail page

[robertu7]

Checklist

• Revise pathname & enums under /a/[shortHash];
• Revise queries (by hash instead of mediaHash or articleId);
• Remove unused redirections (handled by edge https://github.com/thematters/developer-resource/issues/373);

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Story

• https://github.com/thematters/developer-resource/issues/272
• Discussion