feat: Completes hvac-system-performance views and api call.

Sources/Routes/Models/HVACSystemSize.swift

@@ -0,0 +1,11 @@
+public enum HVACSystemSize: Double, Codable, Equatable, Sendable {
+  case one = 1
+  case oneAndAHalf = 1.5
+  case two = 2
+  case twoAndAHalf = 2.5
+  case three = 3
+  case threeAndAHalf = 3.5
+  case four = 4
+  case fourAndAHalf = 4.5
+  case five = 5
+}