cmd: Move build info that is currently stored next to version command into separate file

[Wondertan]

Let's move all the build-related stuff to a related cmd package. Some of the build related info(filled with ldflags) is stored in cmd/celestia/version.go and should be moved to cmd/info.go

[0xJepsen]

Can I give this a try?

[renaynay]

Sure go ahead @0xJepsen

[0xJepsen]

Where should the new printBuildInfo in the new info.go file be called?