Draft: update layout for Latest and Categories cards

What changed

• Cards in the Latest page are no longer randomly emphasized (enlarged), but in a StaggeredGridLayout
• Cards in the Latest page and the Categories page are themed with the typography theme defined in the Theme.App.
• Summaries are no longer confused with the app name, but contrasted with colors
• Summaries in cards in the Categories page are not shown

Old	New

Why

• Theming a general typography theme makes it clear, consistent, and themeable. So future theming changes could be easily injected in a consistent way.
• Cards shouldn't be emphasized in a random manner, which makes no sense but confusions.