Queue: Make WorkerPools and Queues flushable (#10001)

* Make WorkerPools and Queues flushable

Adds Flush methods to Queues and the WorkerPool
Further abstracts the WorkerPool
Adds a final step to Flush the queues in the defer from PrintCurrentTest
Fixes an issue with Settings inheritance in queues

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Change to for loop

* Add IsEmpty and begin just making the queues composed WorkerPools

* subsume workerpool into the queues and create a flushable interface

* Add manager command

* Move flushall to queue.Manager and add to testlogger

* As per @guillep2k

* as per @guillep2k

* Just make queues all implement flushable and clean up the wrapped queue flushes

* cope with no timeout

Co-authored-by: Lauris BH <lauris@nix.lv>

integrations/testlogger.go

@@ -5,6 +5,7 @@
 package integrations
 
 import (
+	"context"
 	"encoding/json"
 	"fmt"
 	"os"
@@ -12,8 +13,10 @@ import (
 	"strings"
 	"sync"
 	"testing"
+	"time"
 
 	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/queue"
 )
 
 var prefix string
@@ -98,6 +101,9 @@ func PrintCurrentTest(t testing.TB, skip ...int) func() {
 	}
 	writerCloser.setT(&t)
 	return func() {
+		if err := queue.GetManager().FlushAll(context.Background(), 20*time.Second); err != nil {
+			t.Errorf("Flushing queues failed with error %v", err)
+		}
 		_ = writerCloser.Close()
 	}
 }