updated api-versions endpoint openapi: put common structure of path and referenced in other openapis

SOL003_90/91: Minimum cardinality of resource attribute set to 2 in "PlacementConstraint" and "VimConstraint"

SOL003_127: 200 Response has been added in GET method on "subscriptions" ressource  (Virtualized Resources Quota Available Notification interface)

SOL003_125 SOL003_126: 200 Response description has been updated in some GET methods (VNF Package Management interface)

SOL003_122 SOL003_123 SOL003_124: 200 Response description has been updated in some GET methods (VNF Indicator interface)

SOL003_120 SOL003_121: 200 Response description has been updated in some GET methods (VNF Fault Management interface)

SOL003_117 SOL003_118 SOL003_119: 200 Response description has been updated in some GET methods (VNF Performance interface)

SOL003_114 SOL003_115 SOL003_116 : 200 Response description has been updated in some GET methods (VNF LCM interface)

SOL003_108: New parameter "nextpage_opaque_marker" in request : GET method on "subscriptions" ressource + Filter implementation

SOL003_99: New parameter "nextpage_opaque_marker" in request : GET method on "vnf_packages" ressource + Filter implementation

SOL003_95: New parameter "nextpage_opaque_marker" in request : GET method on "vnf_packages" ressource + Filter implementation

SOL003_83: New parameter "nextpage_opaque_marker" in request : GET method on "subscriptions" ressource + Filter implementation

SOL003_79: New parameter "nextpage_opaque_marker" in request : GET method on "indicators" ressource + Filter implementation