Crudely fix crashes when switching between TestResultsWithPlayer cases

In the visual test browser, if two `TestResultsWithPlayer` test cases
are ran consecutively, the second would die on `SoloStatisticsWatcher`
seeing duplicated online score IDs. This surfaced after
6ef39b8, which changed
`TestResultsScreen` to inherit `SoloResultsScreen` rather than
`ResultsScreen`.

This is probably _not_ a very good fix, but I'm trying to be pragmatic
for now. `SoloStatisticsWatcher` should probably not live in
`OsuGameBase`.

osu.Game.Tests/Visual/Ranking/TestSceneResultsScreen.cs

@@ -69,6 +69,8 @@ public void TestScaling()
             }));
         }
 
+        private int onlineScoreID = 1;
+
         [TestCase(1, ScoreRank.X)]
         [TestCase(0.9999, ScoreRank.S)]
         [TestCase(0.975, ScoreRank.S)]
@@ -81,14 +83,17 @@ public void TestResultsWithPlayer(double accuracy, ScoreRank rank)
         {
             TestResultsScreen screen = null;
 
-            var score = TestResources.CreateTestScoreInfo();
+            loadResultsScreen(() =>
+            {
+                var score = TestResources.CreateTestScoreInfo();
 
-            score.OnlineID = 1234;
-            score.HitEvents = TestSceneStatisticsPanel.CreatePositionDistributedHitEvents();
-            score.Accuracy = accuracy;
-            score.Rank = rank;
+                score.OnlineID = onlineScoreID++;
+                score.HitEvents = TestSceneStatisticsPanel.CreatePositionDistributedHitEvents();
+                score.Accuracy = accuracy;
+                score.Rank = rank;
 
-            loadResultsScreen(() => screen = createResultsScreen(score));
+                return screen = createResultsScreen(score);
+            });
             AddUntilStep("wait for loaded", () => screen.IsLoaded);
             AddAssert("retry overlay present", () => screen.RetryOverlay != null);
         }