Improve card readability

[hojjatabdollahi]

This is a suggestion. Feel free to close it.
Currently the cards look too dense and too cluttered.

• The height of the cards is too short, the description gets too close to the bottom
• We don't have a dimmed secondary text token in the theme. The body and caption text are way too similar making the cards unreadable.

Here's what I did:

• I added a description_text_style that is dimmed a bit (similar to how it's done for the shortcut keys in the context menus in libcosmic).
• Made the description text font size a bit smaller too.
• Made the text ellipsize instead of just cut off.
• and made the card taller.
• Also looks like the recent changes introduced some formatting and clippy issues, I fixed those in a separate commit.

To me it looks cleaner and less headache-y. :D

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After:

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