[PM-22104] Migrate default collection when org user is removed (#6135)

* migrate default collection to a shared collection when users are removed

* remove redundant logic

* fix test

* fix tests

* fix test

* clean up

* add migrations

* run dotnet format

* clean up, refactor duplicate logic to sproc, wip integration test

* fix sql

* add migration for new sproc

* integration test wip

* integration test wip

* integration test wip

* integration test wip

* fix integration test LINQ expression

* fix using wrong Id

* wip integration test for DeleteManyAsync

* fix LINQ

* only set DefaultUserEmail when it is null in sproc

* check for null

* spelling, separate create and update request models

* fix test

* fix child class

* refactor sproc

* clean up

* more cleanup

* fix tests

* fix user email

* remove unneccesary test

* add DefaultUserCollectionEmail to EF query

* fix test

* fix EF logic to match sprocs

* clean up logic

* cleanup

util/Migrator/DbScripts/2025-08-04-00_OrgUsers_MigrateDefaultCollection.sql

@@ -0,0 +1,22 @@
+CREATE OR ALTER PROCEDURE [dbo].[OrganizationUser_MigrateDefaultCollection]
+    @Ids [dbo].[GuidIdArray] READONLY
+AS
+BEGIN
+    SET NOCOUNT ON
+    DECLARE @UtcNow DATETIME2(7) = GETUTCDATE();
+
+    UPDATE c
+    SET
+        [DefaultUserCollectionEmail] = CASE WHEN c.[DefaultUserCollectionEmail] IS NULL THEN u.[Email] ELSE c.[DefaultUserCollectionEmail] END,
+        [RevisionDate] = @UtcNow,
+        [Type] = 0
+    FROM
+        [dbo].[Collection] c
+        INNER JOIN [dbo].[CollectionUser] cu ON c.[Id] = cu.[CollectionId]
+        INNER JOIN [dbo].[OrganizationUser] ou ON cu.[OrganizationUserId] = ou.[Id]
+        INNER JOIN [dbo].[User] u ON ou.[UserId] = u.[Id]
+        INNER JOIN @Ids i ON ou.[Id] = i.[Id]
+    WHERE
+        c.[Type] = 1
+END
+GO