Fix adding parameter definitions by entity class id

[soininen]

This PR fixes a Traceback that would occur when parameter definitions were added using entity class id instead of name.

Fixes irena-flextool/flextool#228

Checklist before merging

• [x] Documentation (also in Toolbox repo) is up-to-date
• [x] Release notes have been updated
• [x] Unit tests have been added/updated accordingly
• [x] Code has been formatted by black & isort
• [x] Unit tests pass

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 79.13%. Comparing base (bd929d0) to head (2665daa). Report is 4 commits behind head on master.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #454 +/- ## ======================================= Coverage 79.13% 79.13% ======================================= Files 77 77 Lines 10096 10099 +3 Branches 2142 2142 ======================================= + Hits 7989 7992 +3 Misses 1756 1756 Partials 351 351 ```

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