Small improvements to Image handling

[TobiGr]

What is it?

• Bugfix (user facing)
• Codebase improvement (dev facing)

Description of the changes in your PR

• Use constants for unknown image dimensions in ImageStrategy.
• Changes the order of image dimensions in the DescriptionFragement. width x height replaces height x width. width x height is usually used for digital images (e.g. see Wikipedia for PNG and in the graphics industry. height x width is used for frames and analog paintings as well as in data processing and machine learning contexts (numpy, ...). I think we should stick to the order that is commonly used for digital media. The underlying issue is that the Image class uses the wrong order in its constructor, too.

Before/After Screenshots/Screen Record

• Before:
• After:

APK testing

The APK can be found by going to the "Checks" tab below the title. On the left pane, click on "CI", scroll down to "artifacts" and click "app" to download the zip file which contains the debug APK of this PR. You can find more info and a video demonstration on this wiki page.

Due diligence

• I read the contribution guidelines.
• The proposed changes follow the AI policy.
• I tested the changes using an emulator or a physical device.

[theimpulson]

Thank you!