* SECURITY: Update default allowed iframes list
Change the default iframe url list to all include 3 slashes.
* SECURITY: limit group tag's name length
Limit the size of a group tag's name to 100 characters.
Internal ref - t/130059
* SECURITY: Improve sanitization of SVGs in Onebox
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Co-authored-by: Blake Erickson <o.blakeerickson@gmail.com>
Co-authored-by: Régis Hanol <regis@hanol.fr>
Co-authored-by: David Taylor <david@taylorhq.com>