Detect infinite recursion in Entity.to_xml

Summary

Addresses https://gitlab.indiscale.com/caosdb/customers/f-fit/management/-/issues/96 / https://gitlab.com/linkahead/linkahead-pylib/-/issues/73
When calling to_xml on an Entity that refers to itself, to_xml now detects the infinite recursion and stops after the first level of repeated information.

Focus

• What is the likelihood that a version refers to itself (predecessor / successor)? Do we need to add the same functionality to Version.to_xml?
• Does this change anything for Entities that could already successfully call to_xml before? Are there cases where this might break the communication with the server?

Test Environment

Manual Testing

Check List for the Author

• All automated tests pass
• Reference related issues
• Up-to-date CHANGELOG.md (or not necessary)
• Up-to-date JSON schema (or not necessary)
• Appropriate user and developer documentation (or not necessary)
• Annotations in code (Gitlab comments)

Check List for the Reviewer

• I understand the intent of this MR
• All automated tests pass
• Up-to-date CHANGELOG.md (or not necessary)
• Appropriate user and developer documentation (or not necessary)
• 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 specifications? Are they satisfied?

assigned to @i.nueske

added 1 commit

• 4fbc941c - MNT: Revert unwanted behaviour change introduced by bugfix in to_xml with lists of entities

Compare with previous version

added 1 commit

• a7847363 - MNT: Revert unwanted behaviour change introduced by bugfix in to_xml with lists of entities

Compare with previous version

marked the checklist item Annotations in code (Gitlab comments) as completed

requested review from @florian

resolved all threads

added 1 commit

• 8778db51 - DOC: Fix docstring and inline comment

Compare with previous version

marked the checklist item I understand the intent of this MR as completed

marked the checklist item All automated tests pass as completed

marked the checklist item Up-to-date CHANGELOG.md (or not necessary) as completed

marked the checklist item Appropriate user and developer documentation (or not necessary) as completed

marked the checklist item In-code documentation and comments are up-to-date. as completed

added 9 commits

• 8778db51...4ba40593 - 8 commits from branch dev
• cc0221ac - Merge branch 'dev' into f-bug-fit-96-print-recursion

Compare with previous version

marked the checklist item The test environment setup works and the intended behavior is reproducible in the test as completed

added 2 commits

• 7c96253a - MAINT: Change ellipses to etree.Comment
• 063d186f - TST: Test for XML comment text

Compare with previous version

enabled an automatic merge when all merge checks for 063d186f pass

mentioned in commit 2f7cb996

merged