Highlight game cover with different colors based on completion status

[sue-26]

Pre-Request Checklist

• I have checked that this feature is not already available using the ThemeModifier plugin.
• I have checked Playnite's settings (e.g., in Settings -> Appearance) and confirmed that this change cannot be made there.

Feature Description

Each status gets a subtle colored border, glow, or overlay tint on the cover art

for example:
• 🟦 Plan to play – Blue
• 🟩 Playing – Green
• 🟨 Completed – Gold/Yellow
• 🟥 Dropped – Red
• 🟪 On Hold– Purple

Screenshots or Mockups