Feature: Add portal languages preference

[syphax-bouazzouni]

Depend on PL

• Refactor: Queries module code refactor #117

Goal

Define a preference list of languages to choose to print/show in the portal.

So if we set the languages configuration variable like so @@main_languages = ["en", "fr"], the API will show only English values and values with no language tags.
And secondly, if no English or language-tagged values found we print french values.
Else print all the values.

Agroportal and SIFRportal use case

1. At SIFRportal we use this feature to give priority to French values ( using this configuration: @@main_languages = ["fr"] )
2. At Agrportal we choose to have french as a secondary language ( with the fact that in most cases our ontologies are in English or French), so we have set the main_languages to ["en", "fr"] so that if at Agroportal we have an ontology that is only in French, Spanish and German we will print French values.

Related issues

• update multilingual classes prefLabel defaults ontoportal-lirmm/goo#6
• Search test done is inconsistent as it test deprecated or multilingual classes that are not indexed agroportal/project-management#223
• Incorrect label for a property is chosen when multiple language labels are defined ontologies_linked_data#114
• Give preference to English language tags for property labels #95
• Incorrect prefLabel chosen when multiple language labels are defined ontologies_linked_data#91

[alexskr]

@mdorf please review this PR, we should merge it next

[syphax-bouazzouni]

replace with #150