WIP: Attempt at breaking out some logic / middleware between database and view layer, to remove some code from the view controller. Not complete, maybe revert.

Sources/ProjectClient/DuctCalcClientError.swift

@@ -0,0 +1,9 @@
+import Foundation
+
+public struct DuctCalcClientError: Error {
+  public let reason: String
+
+  public init(_ reason: String) {
+    self.reason = reason
+  }
+}