BHV-12598: Handle capitalization of strings in JS instead of CSS.

Issue
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We removed all CSS rules for capitalization (`text-transform:uppercase` and `text-transform:capitalize`) to normalize localization, but missed it in `moon.Divider`.

Fix
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The `text-transform:capitalize` rule has been removed and we are programmatically capitalizing the content string.

Note
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The `text-transform:capitalize` rule uppercases every word, instead of just the first character, and is the reason we are performing extra string processing to mimic the original behavior.

Enyo-DCO-1.1-Signed-off-by: Aaron Tam <aaron.tam@lge.com>
Calling `set`will cause contentChanged to be called again and the string re-capitalized. Directly updating the property would be better. Also, there should also be a call to the super otherwise run-time changes to content won't update the DOM.