[FEATURE] Add Locale Type Converter (Revision 1)

This adds a Type Converter which converts from locale
identifier strings to an actual I18n\Locale object.

Change-Id: I9bd4412bf79878484ac19b61eaed8ef7a13c1437
Releases: master
Revision-Id: 77fae409826fb50c71f6abf605307f823b1288a1