Add AngelPS1::Chrome
Flags and Color are subclass of AngelPS1::Chrome
main: migrate from AngelPS1::Color to ::Chrome
Compiler (and its users): migrate from ::Color to ::Chrome

Migrate the AngelPS1::Compiler from AngelPS1::Color to ::Chrome.
Migrate the builders of sources for the prompt compiler that use colors:
- plugins: AngelPS1::Plugin::Git
- the default prompt: AngelPS1::Prompt::Default
- examples/