SW-4391 split sig and image files

[amrithvenkat]

• Split MigrationOS from the sig file.
• Pass USB_ROOT as a parameter to the caller migration script.
• Use specific colors in the status fail calls, status progress calls.
• Bump version of migration.sh script.
• Status fail will alternate indefinitely between specific color and red based on error.
• Status progress blue for phase 1 of migration.
• Status progress orange for phase 2 of migration.