Implement support for Masque

[Backupiseasy]

Masque support for all icons (e.g. class icons, totem icons, maybe even auras)

• https://wow.curseforge.com/projects/tidy-plates-threat-plates?comment=1550
  • Thank's for your reply, I didn't know about Clean Icons so I'm gonna use that while waiting for a Masque support hopefully.
• https://www.curseforge.com/wow/addons/tidy-plates-threat-plates?comment=5749
  • Would be great if Masque icon skins could be applied to the castbar spell icons :D
• http://www.wowinterface.com/downloads/fileinfo.php?id=15749#comments
  • Castbar spell icon not skinning
• https://www.curseforge.com/wow/addons/tidy-plates-threat-plates/issues/236
  • Add masque support, to skin the icons to match the rest of the ui.
• https://legacy.curseforge.com/wow/addons/tidy-plates-threat-plates?comment=7070
  • how does the spell aura support masque？

[Backupiseasy]

Masque support for ClassIconWidget is implemented; totem icons are also possible. For spell icons, I think TidyPlates must support it - I think I will open a ticket for this.

[suicidalkatt]

I'll be investigating a solution for making this a viable feature.