Hints for oxygen-icons in testing

Hints

• asv-summary-has-dot-suffix
  :38 - سمة أيقونات حرة ومفتوحة المصدر للاستخدام مع نمط بلازما الأكسجين.
  The component summary should not end with a dot (`.`).
• asv-summary-has-dot-suffix
  :47 - Een gratis en open-source pictogramthema voor gebruik met de Oxygen Plasma-stijl.
  The component summary should not end with a dot (`.`).
• asv-summary-has-dot-suffix
  :49 - Um tema de ícones gratuito e de código aberto para usar com o estilo Oxygen Plasma.
  The component summary should not end with a dot (`.`).
• asv-unknown-tag
  :79 - developer
  Found invalid tag. Non-standard tags should be prefixed with `x-`. AppStream also provides the <custom/> tag to add arbitrary custom data to metainfo files. This tag is read by AppStream libraries and may be useful instead of defining new custom toplevel or `x-`-prefixed tags if you just want to add custom data to a metainfo file.