Add validations

[borismod]

Since TOSCA Service Templates can import (or substitute in) other Service Templates, TOSCA Orchestrators and tooling will encounter the “tosca_definitions_version” statement for each imported template. In these cases, the following additional requirements apply:

o Imported type definitions with the same Namespace URI, local name and version SHALL be equivalent.
o If different values of the “tosca_definitions_version” are encountered, their corresponding type definitions MUST be uniquely identifiable using their corresponding Namespace URI using a different Namespace prefix.
· Duplicate local names (i.e., within the same Service Template SHALL be considered an error. These include, but are not limited to duplicate names found for the following definitions:
o Repositories (repositories)
o Data Types (data_types)
o Node Types (node_types)
o Relationship Types (relationship_types)
o Capability Types (capability_types)
o Artifact Types (artifact_types)
o Interface Types (interface_types)
· Duplicate Template names within a Service Template’s Topology Template SHALL be considered an error. These include, but are not limited to duplicate names found for the following template types:
o Node Templates (node_templates)
o Relationship Templates (relationship_templates)
o Inputs (inputs)
o Outputs (outputs)
o Groups (groups)
· Duplicate names for the following keynames within Types or Templates SHALL be considered an error. These include, but are not limited to duplicate names found for the following keynames:
o Properties (properties)
o Attributes (attributes)
o Artifacts (artifacts)
o Requirements (requirements)
o Capabilities (capabilities)
o Interfaces (interfaces)