Feature: Add SemanticArtefactCatalog model (#183)

* add semantic catalog model

* define all the attributes in the catalog scheme

* use default attributes from the catalog scheme yaml file

* fix catalog tests

* ajouter calucaltion of some computed attributes

* Fixing the SemanticArtefactCatalog model structure and code

* update the SemanticArtefactCatalog model and scheme

* remove default values from fundedBy and federated_portals

* fix tests in test_class.rb

* make the ui_host a url

* remove https from the ui_host config

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Co-authored-by: Syphax bouazzouni <[email protected]>