Update script to handle MR on complex cases.

.gitlab/ci/shared_script.gitlab-ci.yml

 .download_dependency:
+  # Note:
+  # For this script to work you need to define teh following variables
+  #  - DEPENDENCY_NAME: Name of the dependency project
+  #  - DEPENDENCY_JOB: Name of the dependency job from which you want to pull artifacts
   script:
     - DEFAULT_BRANCH="dev"
     # Check if a branch with the same name exist on the dependance repository
-    - RESPONSE_CODE=$(curl -s -o /dev/null -w "%{http_code}" "https://gitlab.eclipse.org/eclipse/aidge/$DEPENDENCY_NAME/-/tree/$CI_COMMIT_REF_NAME")
     - >
       if [ "$CI_MERGE_REQUEST_ID" ]; then
-        # Pulling from target branch
-        echo "Pull from ${$CI_MERGE_REQUEST_TARGET_BRANCH_NAME}"
-        curl --location --output build_artifacts.zip "https://gitlab.eclipse.org/api/v4/projects/$CI_PROJECT_ID/jobs/artifacts/$CI_MERGE_REQUEST_TARGET_BRANCH_NAME/download?job=$JOB"
-      elif [ "$RESPONSE_CODE" -eq 404 ]; then
+        if [ $(curl -s -o /dev/null -w "%{http_code}" "https://gitlab.eclipse.org/eclipse/aidge/$CI_MERGE_REQUEST_TARGET_BRANCH_NAME/-/tree/$CI_COMMIT_REF_NAME") -eq 404 ]; then
+          echo "Pull from ${DEFAULT_BRANCH}"
+          curl --location --output build_artifacts.zip "https://gitlab.eclipse.org/api/v4/projects/$CI_PROJECT_ID/jobs/artifacts/$DEFAULT_BRANCH/download?job=$JOB"
+        else
+          # Pulling from target branch
+          echo "Pull from ${CI_MERGE_REQUEST_TARGET_BRANCH_NAME}"
+          curl --location --output build_artifacts.zip "https://gitlab.eclipse.org/api/v4/projects/$CI_PROJECT_ID/jobs/artifacts/$CI_MERGE_REQUEST_TARGET_BRANCH_NAME/download?job=$JOB"
+        fi
+
+      elif [ $(curl -s -o /dev/null -w "%{http_code}" "https://gitlab.eclipse.org/eclipse/aidge/$DEPENDENCY_NAME/-/tree/$CI_COMMIT_REF_NAME") -eq 404 ]; then
         echo "Pull from ${DEFAULT_BRANCH}"
         curl --location --output build_artifacts.zip "https://gitlab.eclipse.org/api/v4/projects/$CI_PROJECT_ID/jobs/artifacts/$DEFAULT_BRANCH/download?job=$JOB"
       else