Password management with Basic Auth plugin

[PGBI]

• Kong is returning hashed passwords when requesting GET /consumers/{id}/basic-auth. Instead of displaying the hash, which is useless and misleading, nothing or ****** should be displayed.
• Kong dashboard does not give the possibility to choose a password for basic auth, assuming Kong will auto generate one. Because of this Kong issue [basic-auth] auto-generated passwords are identical Kong/kong#772 , auto generated password are empty. So Kong dashboard should let the user choose a password.