Player models improvements

• Bring back shirt color in fullbright player models (added some more shirt color to erebus and nyx since they were 95% glow color)
• Add fullbright versions of shadowhead and ignishead (used by 6 player models)
• Fix mixed shirt and glow colors on the ankle for pyria and umbra (normal and fullbright) models and on the shoulder blades for umbra (normal and fullbright)
• Fix less saturated glow colors of ignis and seraphina (normal and fullbright) due to overlapped base and glow textures
• Add a bit more glow color to all gak models