Update-ModuleManifest FunctionsToExport should be a single item per line

[codykonior]

Steps to reproduce

If you are using Update-ModuleManifest with FunctionsToExport it can combine multiple array entries onto a single line.

This sounds good in theory but in practice it causes a lot of problems with line-based source control like git.

It prevents merges from happening cleanly automatically, and then for doing manual merges it becomes difficult to spot the missing/extra function in the list when there's 2 or 3 crammed into each line.

I think it should split one entry per line.