* Moves ColorSystem from Profile to Capabilities
* Renames Tty to IsTerminal
* Adds IAnsiConsoleOutput to make output more flexible
Closes#343Closes#359Closes#369
This makes it possible for encoders to output better representation
of the actual objects instead of working with chopped up segments.
* IAnsiConsole.Write now takes an IRenderable instead of segments
* Calculating cell width does no longer require a render context
* Removed RenderContext.LegacyConsole
* Removed RenderContext.Encoding
* Added Capabilities.Unicode
