Dragonflight

[p3lim]

This should contain most, if not all of the fixes and features for Dragonflight. We'll also merge in any other branches from the 11 milestone if time allows it.

[p3lim]

TODO (according to @ls-):

• [x] castbars needs some tweaking
• [x] docs needs updating
• [x] merge #592
• [x] more testing (we should have an example layout that covers everything tbh)

[ls-]

Code-wise I think we're ready. Just to clarify on a couple of things.

• I chose against implementing cooldowns for the Essence classpower. The way Blizz implemented them is honestly wack, so overcomplicating the element to support that wasn't worth it. If you want them, use PostUpdate and GetPowerRegenForPowerType to show the "cooldown".

• Castbar empowerment stages. We only add pips to the element, if you need fancy colouring like in the default UI, use those pips as anchors (they're frames. at least by default), that's what the default UI does as well. Both horizontal and vertical bars are supported, the reverse fill is supported as well.

• Despite how complex auras changes might look, the way the element works now is pretty straightforward. Also, its performance isn't an issue, on average (full and partial updates combined) the new implementation is 30% faster than what we had previously, and even that wasn't slow either. For instance, here's the avg performance per call after 1k calls with like 24-32 active auras:

So what's left is to update the documentation where it's outdated or missing.

[p3lim]

Posted upgrade guide: https://www.wowinterface.com/forums/showthread.php?t=59273