Just checking one string, same name as function, don't need a function.

Again, shrinking server package so it's easier to test when we refactor database stuff.

The function named buildPackage wasn't really clear what was going on: each named file was being parsed by the Go parser. Parsing files has nothing to do with the server implementation. Moving stuff out of the server package now will make modifying how the server deals interacts with the database easier.

No hard line length limit in Go

It was only ever used for one log message. We still keep the maximum file size to fetch, though, but the server doesn't need to know about it. While here use regular http.Client.Head as only context.TODO was ever provided.

One less dependency to document, and all it did was run a single go command anyway.