Reload Edit Mode toolbox after creating RTs and Properties

Summary

Newly created RTs and Properties were missing in the lists of the edit mode toolbox. No longer.

Fixes #117 (closed) and #202 (closed)

Focus

Point the reviewer to the core of the code change. Where should they start
reading? What should they focus on (e.g. security, performance,
maintainability, user-friendliness, compliance with the specs, finding more
corner cases, concrete questions)?

Test Environment

Create an RT and a Property and check that they were added.

Check List for the Author

Please, prepare your MR for a review. Be sure to write a summary and a focus and create gitlab comments for the reviewer. They should guide the reviewer through the changes, explain your changes and also point out open questions. For further good practices have a look at our review guidelines

• All automated tests pass
• Reference related Issues
• Up-to-date CHANGELOG.md
• Annotations in code (Gitlab comments)
  • Intent of new code
  • Problems with old code
  • Why this implementation?

Check List for the Reviewer

• I understand the intent of this MR
• All automated tests pass
• Up-to-date CHANGELOG.md
• The test environment setup works and the intended behavior is reproducible in the test environment
• In-code documentation and comments are up-to-date.
• Check: Are there spezifications? Are they satisfied?
• discard the branch f-update-edit-mode-toolbox if you are satisfied with this MR; it implements the same in a different way

For further good practices have a look at our review guidelines.