Break out xcode-locator's main function into smaller chunks.
Break out xcode-locator's main function into smaller chunks.

This is intended to be a refactoring without functional changes for my
own sanity in understanding what this code does.  Except I couldn't
avoid applying some visual improvements to the usage message.

RELNOTES: None.
PiperOrigin-RevId: 206771539

ulfjack/bazel,davidzchen/bazel,perezd/bazel,perezd/bazel,dropbox/bazel,meteorcloudy/bazel,ulfjack/bazel,safarmer/bazel,akira-baruah/bazel,ulfjack/bazel,meteorcloudy/bazel,katre/bazel,bazelbuild/bazel,dslomov/bazel,cushon/bazel,meteorcloudy/bazel,twitter-forks/bazel,aehlig/bazel,ButterflyNetwork/bazel,twitter-forks/bazel,ButterflyNetwork/bazel,akira-baruah/bazel,bazelbuild/bazel,ButterflyNetwork/bazel,bazelbuild/bazel,davidzchen/bazel,meteorcloudy/bazel,werkt/bazel,akira-baruah/bazel,perezd/bazel,cushon/bazel,akira-baruah/bazel,ulfjack/bazel,ulfjack/bazel,twitter-forks/bazel,dropbox/bazel,katre/bazel,bazelbuild/bazel,katre/bazel,ulfjack/bazel,aehlig/bazel,twitter-forks/bazel,aehlig/bazel,ulfjack/bazel,werkt/bazel,dslomov/bazel,ButterflyNetwork/bazel,katre/bazel,safarmer/bazel,aehlig/bazel,cushon/bazel,davidzchen/bazel,meteorcloudy/bazel,bazelbuild/bazel,dslomov/bazel,akira-baruah/bazel,katre/bazel,werkt/bazel,perezd/bazel,perezd/bazel,dslomov/bazel-windows,perezd/bazel,werkt/bazel,safarmer/bazel,cushon/bazel,perezd/bazel,aehlig/bazel,dslomov/bazel,dslomov/bazel-windows,dslomov/bazel-windows,davidzchen/bazel,akira-baruah/bazel,twitter-forks/bazel,werkt/bazel,dslomov/bazel,meteorcloudy/bazel,twitter-forks/bazel,bazelbuild/bazel,safarmer/bazel,cushon/bazel,dslomov/bazel-windows,davidzchen/bazel,dropbox/bazel,dropbox/bazel,dslomov/bazel,ButterflyNetwork/bazel,dropbox/bazel,katre/bazel,ButterflyNetwork/bazel,cushon/bazel,dslomov/bazel-windows,dropbox/bazel,dslomov/bazel-windows,werkt/bazel,aehlig/bazel,twitter-forks/bazel,davidzchen/bazel,safarmer/bazel,davidzchen/bazel,dslomov/bazel,safarmer/bazel,aehlig/bazel,meteorcloudy/bazel