Refactor generic_combinations initialization logic

Refactor generic_combinations assignment to handle presence in config.

Signed-off-by: Dario Pranjic <96529060+Knerio@users.noreply.github.com>

Author: Knerio

build/ruby/lib/tucana/shared/shared.data_type.rb

@@ -248,7 +248,14 @@ def from_hash(config)
         self.source = config[:source].map do |source|
           DataTypeIdentifier.from_hash(source)
         end
-        self.generic_combinations = config.fetch(:generic_combinations, [])
+        
+        self.generic_combinations = []
+        if config.key?(:generic_combinations)
+          config[:generic_combinations].each do |combo|
+            self.generic_combinations << combo
+          end
+        end
+        
         self
       end