Adds two custom tracks from the ULTRAKILL encore levels (that we have so far).

"A Heart of Cold" - from [0-E: THIS HEAT, AN EVIL HEAT]

• "A Heart of Cold" for stealth and control
• "Dead Heat Pulse" for assault

"An Absence / A Part Falling" - from [1-E: ...THEN FELL THE ASHES]

• "An Absence" for stealth and control
• "A Part Falling" for anticipation and assault

Both tracks use their respective song's "calm" variant for stealth, and "action" variant for control. Mostly pretty simple stuff since the game's soundtrack files are already looped for me.

All credits go to Hakita/Heaven Pierce Her, the creator of ULTRAKILL and its soundtrack.