add test to check /smach_viewer/image

[k-okada]

It fails on WSL, but not able to reproduce on native Linux machine...

(smach_viewer.py:5590): Gtk-WARNING **: 14:23:59.439: Error loading theme icon 'document-save' for stock: Icon 'document-save' not present in theme Adwaita
[Testcase: testsmach_viewer_test] ... ok

[ROSTEST]-----------------------------------------------------------------------

[smach_viewer.rosunit-smach_viewer_test/test_publish][FAILURE]------------------
Topic [/smach_viewer/image] is not published
  File "/usr/lib/python3.8/unittest/case.py", line 60, in testPartExecutor
    yield
  File "/usr/lib/python3.8/unittest/case.py", line 676, in run
    self._callTestMethod(testMethod)
  File "/usr/lib/python3.8/unittest/case.py", line 633, in _callTestMethod
    method()
  File "/opt/ros/noetic/share/rostest/nodes/publishtest", line 141, in test_publish
    assert ret, 'Topic [%s] is not published' % (checker.topic_name)
--------------------------------------------------------------------------------

here is workaround

commit e2ee0fdd46ccf1b53e1f01d71ff5d0dc5fe36ef7 (HEAD -> fix_pub_image)
Author: Kei Okada <[email protected]>
Date:   Tue Feb 11 18:02:46 2025 +0900

    scirpt/smach_viewer: fix smach_viewer crashes when subscribe smach_viewer/image

diff --git a/smach_viewer/scripts/smach_viewer.py b/smach_viewer/scripts/smach_viewer.py
index 556de5b..c27afb8 100755
--- a/smach_viewer/scripts/smach_viewer.py
+++ b/smach_viewer/scripts/smach_viewer.py
@@ -642,10 +642,11 @@ class SmachViewerFrame(wx.Frame, SmachViewerBase):
         memory.Blit(0, 0, x, y, context, 0, 0)
         memory.SelectObject(wx.NullBitmap)
         if LooseVersion(wx.__version__) >= LooseVersion('4.0'):
-            buf = bitmap.ConvertToImage().GetDataBuffer()
+            buf = bitmap.ConvertToImage().GetData()
+            img = np.array(buf)
         else:
             buf = wx.ImageFromBitmap(bitmap).GetDataBuffer()
-        img = np.frombuffer(buf, dtype=np.uint8)
+            img = np.frombuffer(buf, dtype=np.uint8)
         bridge = cv_bridge.CvBridge()
         img_msg = bridge.cv2_to_imgmsg(img.reshape((y, x, 3)), encoding='rgb8')
         img_msg.header.stamp = rospy.Time.now()