feat(backend): add communication, tester, admin and middleman modules

Implement step 17 modules: threads/messages, notifications with automation (submission.created, idea.created, grant_call.opened), innovation test feedback, admin panel (submissions, verify, metrics, grant call status), Middleman adaptation and partnerships. Split multi-type files into one type per file and replace object-valued dictionaries with string-valued maps in data contracts (migrations 0006/0007).

backend/Domain/Rules/PartnershipWorkflow.cs

@@ -0,0 +1,20 @@
+using TarninaHub.Domain.Enums;
+
+namespace TarninaHub.Domain.Rules;
+
+public static class PartnershipWorkflow
+{
+    private static readonly IReadOnlyDictionary<PartnershipStatus, PartnershipStatus[]> Transitions =
+        new Dictionary<PartnershipStatus, PartnershipStatus[]>
+        {
+            [PartnershipStatus.Proposed] = [PartnershipStatus.Active, PartnershipStatus.Closed],
+            [PartnershipStatus.Active] = [PartnershipStatus.Closed],
+            [PartnershipStatus.Closed] = [],
+        };
+
+    public static bool CanTransition(PartnershipStatus from, PartnershipStatus to) =>
+        from == to || Transitions[from].Contains(to);
+
+    public static bool IsTerminal(PartnershipStatus status) =>
+        Transitions[status].Length == 0;
+}