Improve layout of ApplicationPage

• Use various background colors instead of just white
• Add a max width to the description text
• Use the application comment as title for the description
• Replace application comment with author in title
• Increase height of screenshots + add a bit more padding arround it
• Make a few things bolder
• Use ScrollView for the screenshot listview and make it use correct spacing
• Use Card for reviews

Before:

After:

@teams/vdg