Context

As a step of reducing Language and LanguageConverter, the intermediate interface that supplies namespace conversion/formatting should be introduced.

Expected result

• Interface/implementation NamespaceNameLocalizer should be introduced.
• getNamespaces, getFormattedNamespaces, getNsText, getFormattedNsText, getGenderNsText, getLocalNsIndex, getNamespaceIds, etc. should be copied from the Language class.
• NamespaceNameLocalizerFactory with method ::create($languageCode) should be introduced.
• Relevant tests should be moved/copied from LanguageTest class.
• register NamespaceNameLocalizerFactory as service.
• class should be 100% covered by tests