Add Fel Magic/Corruption/Chaos feature to races Demon/Satyr

[tdauth]

https://wowpedia.fandom.com/wiki/Fel

Give them all a Mana Burn/Fel Burn ability -> transfer life for their mana and gives them temporarily stronger attack etc. Fel Corruption. The power can be transferred into non-Demon units, changing their color to red/green. If cast on allies it makes them temporarily stronger. If cast on enemies it also makes them temporarily stronger but changes the owner to neutral hostile for some time.

https://www.hiveworkshop.com/threads/life-burn-and-fel-burn.307400/

Fel corruption should change units:

• Orcs -> Fel/Chaos Orcs
• Treants/Night Elvs -> Corrupted Night Elves with Satyrs. #2027

[tdauth]

Use Ubersplats with the ground texture of corruption from Felwood:

//============================================================================
// Ubersplat API
//
native CreateUbersplat              takes real x, real y, string name, integer red, integer green, integer blue, integer alpha, boolean forcePaused, boolean noBirthTime returns ubersplat
native DestroyUbersplat             takes ubersplat whichSplat returns nothing
native ResetUbersplat               takes ubersplat whichSplat returns nothing
native FinishUbersplat              takes ubersplat whichSplat returns nothing
native ShowUbersplat                takes ubersplat whichSplat, boolean flag returns nothing
native SetUbersplatRender           takes ubersplat whichSplat, boolean flag returns nothing
native SetUbersplatRenderAlways     takes ubersplat whichSplat, boolean flag returns nothing
``