Unify the terminal color output API

[zindel]

Fastpack was started a while ago before Pastel was introduced. Because of this we came up with a limited implementation of the colored output. See FastpackUtil/Terminal.re, specifically print_with_color function.

It would be great to get rid of this function in favour of the Pastel. An example of the Pastel usage in the Fastpack codebase can be seen in Fastpack/Commands.re.

The related issue is the clearScreen function which is known to work on MacOS/Linux terminals, but I totally don't know if it works on Windows. So, it'd be useful to test and fix it to be truly cross-platform.

[Ishaan28malik]

Is it still pending ?
@zindel

[zindel]

@Ishaan28malik, @davesnx has completed the first part. The second part clearScreen is still pending. I.e. if it works on Windows we can safely close it, if it doesn't - the fix would be much appreciated!