GitLab

Fixes issue #2104

The code for `internal/cli/core` and `internal/cli/lib` has been
refactored so that we can use only the `Get` functions from
`internal/cli/outdated` package and compose there composited object.

For regular text output, the new table will have some extra fields that
either for platforms or for libraries will be blank.

For JSON and YAML output, the resulting object will have the top-level
keys `platforms` and `libraries` which contain, respectively, the array
of outaded platforms and outdated libraries.
Signed-off-by: Lluís Martínez <lluis@tastaollet.es>