Skills filtering

I believe we could use an additional filtering option in skill catalogue - a pretty simple one to make browsing skills easier for some pilots - Show/Hide Omega skills.
Such filter shall hide/show Omega Only skills, not those which require Omega status to train past certain level (with consideration whether the skill should be hidden or not once it reached the Omega threshold).
Such filter could as be called “Show alpha skills only” to show only skills trainable by Alpha pilots.
Such filter shall be available as a separate option from current filters so that current filters could be used regardles of Show Alpha filter status.