Enhance GIMP metrics evaluator with logging and transparency handling

- Replaced print statements with logging for better traceability in gimp.py.
- Added handling for transparent images in structure checks and size evaluations.
- Updated JSON examples to include delays in pyautogui commands for improved execution reliability.
- Changed image URL in example to a more accessible source.

evaluation_examples/examples/gimp/f723c744-e62c-4ae6-98d1-750d3cd7d79d.json

@@ -37,7 +37,7 @@
           "command": [
             "python3",
             "-c",
-            "import pyautogui; pyautogui.hotkey([\"shift\", \"ctrl\", \"e\"]);"
+            "import time; import pyautogui; time.sleep(1);pyautogui.hotkey([\"shift\", \"ctrl\", \"e\"]);"
           ]
         }
       },
@@ -53,7 +53,7 @@
           "command": [
             "python3",
             "-c",
-            "import pyautogui; pyautogui.write(\"berries_contrast\");pyautogui.press([\"enter\"]);"
+            "import time; import pyautogui; time.sleep(1);pyautogui.write(\"berries_contrast\");time.sleep(1);pyautogui.press([\"enter\"]);"
           ]
         }
       },
@@ -69,7 +69,7 @@
           "command": [
             "python3",
             "-c",
-            "import pyautogui; pyautogui.press([\"enter\"]);"
+            "import time; import pyautogui; time.sleep(1);pyautogui.press([\"enter\"]);"
           ]
         }
       },