codeintel: Refactor upload package
Created by: efritz
This gives some love to the ./lib/codeintel/utils
package and transforms it into the ./lib/codeintel/upload
package. New code was kept separate in order to make reviewing easy. Please review by commit.
This gives some structure to the output, and also uses the ./lib/output
package used by batch changes to give our utilities a more consistent feel.
Sibling src-cli PR: https://github.com/sourcegraph/src-cli/pull/541