Update color schemes in the demo apps

[MGaetan89]

Pull request

Description

Create new color schemes for the demo, that are closer to the colors of pillarbox-apple.

Changes made

• Create new color schemes (light/dark) in pillarbox-demo-shared
• Use these new color schemes in pillarbox-demo-tv
• Use these new color schemes in pillarbox-demo
• Add support for dynamic colors in pillarbox-demo (the colors are generated dynamically based on the background of the device)
• Update the template of the copyright header to avoid having the year in new files (improvement on top of Remove year from copyright info #301)

Screenshots

Description	Dark mode	Light mode
Dynamic colors (blue, demo)
Dynamic colors (yellow, demo)
Static colors (demo)
Static colors (demo TV)		N/A

Checklist

• Your branch has been rebased onto the main branch.
• APIs have been properly documented (if relevant).
• The documentation has been updated (if relevant).
• New unit tests have been written (if relevant).
• The demo has been updated (if relevant).
• All pull request status checks pass.