Manage duplicated sets of items returned by services

[David-Henandez-nrcan]

The sets of items returned by each query might contain duplicates when both languages 'en/fr' are requested, and this parameter is irrelevant for the service. We can either:

• Bypass the language parameter by calling the specific service with its main language (en).
• going through the lists of returned items to identify and get rid of those which 'id' is duplicated.

[David-Henandez-nrcan]

Changing the parameter 'lang' from 'list' to 'string' and adding 'default' value. fix the problem.

• The parameter must match either of the values from the 'enum' list
• In absence of the parameter, it is included with the 'default' value.