Output parent locales once

[movermeyer]

What are you trying to accomplish?

Fixes #90

What approach did you choose and why?

• Sorted the list of shared components
• Added the ParentLocales to the list of shared locales
• Brought back ParentLocales in Cldr::Export::Data#components (effectively reverting Fix parent locales #40)

When ParentLocales was added, it was added as a locale-based component, but didn't have the same signature of locale-based components (since of course it is a shared component), so it caused an error. This was fixed in IMO the wrong way in #40, by excluding the component from being exported unless explicitly requested.

This brings back the component, and now that it is properly marked as a shared component, it no longer has that error.

What should reviewers focus on?

🤷

The impact of these changes

• ParentLocales is once again exported by default (users of ruby-cldr no longer have to run thor cldr:export and thor cldr:export --components=parentLocales, but instead just the former)
• parent_locales.yml is output in data/ and not under each locale directory.
• Less files, less bytes:

	Before (with explicit --components=parentLocales)	After	Ratio
# of .yml files	6476	5723	0.88
Total bytes	30753892 (29.3 MiB)	28984221 (27.6 MiB)	0.94

Testing

thor cldr:export

See that data/parent_locales.yml exists and contains the same data.

[trishrempel]

👍🏻

[cejaekl]

FWIW, this looks good to me.