Homogenize the progress bar in Pkg and base package precompilation

[KristofferC]

• Fix a missing check to always_reprint that has been fixed in Pkg
• The header was in light_green while in Pkg it was green.
• The progress bar for downloading packages and artifacts was in green while compiling package was in blue.
• The progress bar is now attached to the "Precompiling packages" header like for artifact and package downloads.