workflows: Unicode character handling

* Handles better Unicode characters when searching in Holding Pen.

* Renames variables and functions for clarity.

Signed-off-by: Jan Aage Lavik <jan.age.lavik@cern.ch>
workflows: handle None as workflow name

* Handles better the case when the workflow name is None.

Signed-off-by: Jan Aage Lavik <jan.age.lavik@cern.ch>