New reviewer role per locale

- Introduce translator, reviewer role in locale (HMember_Locale)
- Existing members of locale will be migrate to translator role
- User now can email request to join a language team with roles: translator, reviewer, or coordinator. 
- Existing members can request to update their role in language team
- Updated UI in locale page -> manage members to include new roles, also in locale page -> search members (result)
- Update rules to check isTranslator rather than isMember of a language.
- Update restrictions in workspace for translator/reviewer roles. 
    - Workspace still have only 2 modes - edit, readonly
    - For edit mode, if user is reviewer - only accept and reject buttons enabled
                          , if user is translator - disable accept and reject buttons