Resolve "Using `!dag_prev` after a meta-operation makes the wrong association"

This MR fixes a bug that occurred when:

• using !dag_prev (or any other relative reference) as argument to a meta-operation
• with the meta-operation using that argument in a transformation other than the first transformation.

In such a case, wrong referencing was made because the relative reference was only evaluated after other nodes (from the meta-operation) were added, hence no longer pointing to the desired node.

This was resolved by first replacing all relative references with absolute references before commencing with adding the nodes from the meta-operation specification.

Can this MR be accepted?

• Implementation ready
• Tests added or adjusted
• Documentation extended or updated

• Code quality
  • Changes follow coding guidelines
  • Checked code coverage on new and adjusted code

• Ready for merging
  • Pipeline passes without warnings
  • History cleaned-up or squash option set
  • Changelog entry added
  • Version number bumped

Related issues

Closes #216 (closed)