Detect errors in getProperty/getAttribute/getInput

[jesus-gorronogoitia]

Properties and attributes of node templates in AADMs can get their values by using the functions getProperty/getAttribute/getInput.
Those functions references properties/attributes located at:

• the node referenced by entity (see figure below). So, if entity is SELF and the req_cap is not set, the property names must be located in current template snow_webcam_crawler type hierarchy.
• if req_cap is set in the function declaration, then the property names must be located at the node snow-docker-network that is referenced in the requirement/capability network. But names is not a property declared in the hierarchy of
  the node snow-docker-network and the error should be spotted.
  

Similar error detection for getAttribute and getInput. In case of getInput the referenced input must be one declared within the AADM. Otherwise, an error should be reported.