Place salmon pieces onto cooking sheet lined with aluminum foil. Spray with cooking spray and coat with fresh lemon. Season with salt and chili powder. Place in broiler for 6-7 minutes. While salmon is cooking, place whole pistachios into blender and blend until nuts resemble chunky sand (kind of like chunky peanut butter size). Reserve 2 tablespoons of pistachios to sprinkle on top of wraps. Add yogurt, salt, garlic, lemon/lime juice, and cilantro to blender and blend until desired smoothness. Remove from blender. Place mixture into the corner of a snack size baggie and snip tip with scissor. Place salmon onto lettuce leaves and top with avocado slices. Squeeze pistachio cream onto salmon. Sprinkle with reserved chopped pistachio pieces.