Separate top level explicit exposes by lines [CLI v4.2.2] [Elm v0.5.4]

[JQuezada0]

Once the number of input types grows to a point where concatenating them with a comma and a space causes the line to exceed 65535 characters, elm will fail to parse the file.

This change uses softlines from the elm-pretty-printer package to break up the exposes list as needed, but it prefers one line if possible.