Split the CLI tools so they are extensible in a git-alike way. The tracker repo keeps the following subcommands:
- info
- sparql
- sql
- help
in a single executable, and makes it possible to extend those with other executables installed in $libexec/tracker/. This seems to be the minimal set of subcommands that will apply to tracker databases. With the other commands relying on miners, their dbus services, and their data in different ways.