Federation: return useful statistic information for nodeinfo (#19561)

Add statistic information for total user count, active user count, issue count and comment count for `/nodeinfo`

models/issue_test.go

@@ -590,3 +590,10 @@ func TestLoadTotalTrackedTime(t *testing.T) {
 
 	assert.Equal(t, int64(3682), milestone.TotalTrackedTime)
 }
+
+func TestCountIssues(t *testing.T) {
+	assert.NoError(t, unittest.PrepareTestDatabase())
+	count, err := CountIssues(&IssuesOptions{})
+	assert.NoError(t, err)
+	assert.EqualValues(t, 15, count)
+}