x11-wm/mango: Update to 0.16.3

• Update LICENSE field
• Update list of dependencies
• Update pkg-message:
  1. when installing the port, to notify the incompatibility of this version of Mango with x11/waybar v. 0.15.0
  2. when upgrading the port, to notify some breaking changes too.

ChangeLog:

1. https://github.com/mangowm/mango/releases/tag/0.15.0
2. https://github.com/mangowm/mango/releases/tag/0.15.1
3. https://github.com/mangowm/mango/releases/tag/0.15.2
4. https://github.com/mangowm/mango/releases/tag/0.15.3
5. https://github.com/mangowm/mango/releases/tag/0.15.4
6. https://github.com/mangowm/mango/releases/tag/0.15.5
7. https://github.com/mangowm/mango/releases/tag/0.15.6
8. https://github.com/mangowm/mango/releases/tag/0.16.0
9. https://github.com/mangowm/mango/releases/tag/0.16.1
10. https://github.com/mangowm/mango/releases/tag/0.16.2
11. https://github.com/mangowm/mango/releases/tag/0.16.3

Reported by: DreamMaoMao <notifications@github.com>