TEIIDDES-1612: Fixes accumulation of inputs in transformation

* AttributeMappingHelper
 * The element collector visitor implementations store the returned
   elements in a field. As a consequence, using the visitor in a loop means
   the previously found elements are also returned with newly found
   elements.
 * Creates a new instance of the visitor each time it is required to
   avoiding erroneous caching of elements.
Improves performance of submodule project auto-builders