Currently a substitution mapping is always generated for a service template based on the base type for the service. 

In some use cases there is no need for the substitution mapping. This story is to support the generation of the service template without the substitution mapping where none is required

There are a few aspects to consider:

• During service creation logic must be updated to support the case where no base type exists (e.g. createServiceByDao in ServiceBusinessLogic must be able to handle where derivedFromGenericType is null);
• The generation of the template and csar must be able to handle the situation where there is no derivedFromGenericType by not creating a substitution mapping and not creating the *-interface.yml file which would normally contain the definition of the subsitutable as node type;
• Allow to configure Service Categories that has no base type;
• No properties should be allowed to be created in Services that have no base type, as the properties are added to the substitution_mappings type;
• No substitution filters should be allowed to be created in Services that have no base type.

In summary, allow Service base type to be optional and, when not selected, remove the substitution_mappings section of the service template. For Services without base type, disable the add property (Propertyies Assignment) and substitution filter creation (Composition).