Marinate the shrimp in a bowl with the olive oil, lemon juice, garlic, paprika, salt, and pepper. Heat a grill or grill pan over medium high heat and spray with cooking spray. Grill the shrimp 2-3 minutes on each side until opaque. Remove from heat. Add the tomatoes to the grill and cook a few minutes, turning occasionally, until lightly charred and softened. Toss the cooked fettuccini with about 1 cup of the collard greens pesto. Stir in some of the reserved pasta water until the sauce coats the pasta. Reserve the remaining pesto for another use. Arrange the grilled shrimp and tomatoes on top of the pasta and serve.