Dark mode improvements

[yceballost]

Describe the bug

There are a tones of improvements for dark mode.

This is a list to improve

• Inverse states in display media cards
• Tags
• Hero
• Buttons
• Avatar inverse

Tasks

• [x] #1179

[aweell]

Should we create a issue only for display media and poster to solve the textSecondaryInverse issue in 8.0.1?

Is only an update in the specs + modify poster card PR before merge

[kydorn]

I don't know if this brand-colored link is expected in dark mode (and only in dark mode), but it seems unlikely.