[MODERATION] Add repo transfers to blocked functionality (squash)

- When someone gets blocked, remove all pending repository transfers
from the blocked user to the doer.
- Do not allow to start transferring repositories to the doer as blocked user.
- Added unit testing.
- Added integration testing.

(cherry picked from commit 8a3caac330)
(cherry picked from commit a92b4cfeb6)
(cherry picked from commit acaaaf07d9)
(cherry picked from commit 735818863c)
(cherry picked from commit f50fa43b32)
(cherry picked from commit e166836433)
(cherry picked from commit e0187b21fe)
(cherry picked from commit 697a492686)

services/user/block.go

@@ -5,9 +5,12 @@ package user
 import (
 	"context"
 
+	model "code.gitea.io/gitea/models"
 	"code.gitea.io/gitea/models/db"
 	repo_model "code.gitea.io/gitea/models/repo"
 	user_model "code.gitea.io/gitea/models/user"
+
+	"xorm.io/builder"
 )
 
 // BlockUser adds a blocked user entry for userID to block blockID.
@@ -66,5 +69,27 @@ func BlockUser(ctx context.Context, userID, blockID int64) error {
 		return err
 	}
 
+	// Remove pending repository transfers, and set the status on those repository
+	// back to ready.
+	pendingTransfersIDs, err := model.GetPendingTransferIDs(ctx, userID, blockID)
+	if err != nil {
+		return err
+	}
+
+	// Use a subquery instead of a JOIN, because not every database supports JOIN
+	// on a UPDATE query.
+	_, err = db.GetEngine(ctx).Table("repository").
+		In("id", builder.Select("repo_id").From("repo_transfer").Where(builder.In("id", pendingTransfersIDs))).
+		Cols("status").
+		Update(&repo_model.Repository{Status: repo_model.RepositoryReady})
+	if err != nil {
+		return err
+	}
+
+	_, err = db.GetEngine(ctx).In("id", pendingTransfersIDs).Delete(&model.RepoTransfer{})
+	if err != nil {
+		return err
+	}
+
 	return committer.Commit()
 }