Fix 'langpack' consistency issue
Fix 'langpack' consistency issue

- We use inconsistent terms for languagepack in the CLI
- languagepack commands use 'lp' and 'languagepack'
- app commands use 'lp' and 'langpack'

fixing this inconsistency so both commands use
'lp' and 'languagepack'

Closes-bug: 1441881
Change-Id: I3583a947db4e33297355efb92c692f70a69fa66e

stackforge/python-solumclient,stackforge/python-solumclient,openstack/python-solumclient