fixing bug related to version links

[jm22dogs]

Brief description

When creating a CustomAttributeLink, if there was already a link for that AssetVersion, an error was raised:

2025-02-21 15:00:38:  0: STDOUT: ERROR:ftrack_api.session.Session:Server reported error: DuplicateEntryError(Duplicate entry bbef5b66-23fd-46b8-80b7-768bd244e6bc-45abb5e1-f77d-49e8-8c34-... for CustomAttributeLink unique on from_id, to_id, configuration_id.)
2025-02-21 15:00:38:  0: STDOUT: NoneType: None
2025-02-21 15:00:38:  0: STDOUT: WARNING:ftrack_api.session.Session:Resetting session with pending operations not persisted.
2025-02-21 15:00:38:  0: STDOUT: ERROR:pyblish.plugin:Traceback (most recent call last):
2025-02-21 15:00:38:  0: STDOUT:   File "C:\Program Files (x86)\OpenPype\3.14.10\dependencies\pyblish\plugin.py", line 522, in __explicit_process
2025-02-21 15:00:38:  0: STDOUT:     runner(*args)
2025-02-21 15:00:38:  0: STDOUT:   File "C:\Users\22deadline.AD\AppData\Local\pypeclub\openpype\3.14\openpype-v3.14.11-22dogs.150+staging\openpype\modules\ftrack\plugins\publish\integrate_ftrack_api.py", line 103, in process
2025-02-21 15:00:38:  0: STDOUT:   File "C:\Users\22deadline.AD\AppData\Local\pypeclub\openpype\3.14\openpype-v3.14.11-22dogs.150+staging\openpype\modules\ftrack\plugins\publish\integrate_ftrack_api.py", line 246, in integrate_to_ftrack
2025-02-21 15:00:38:  0: STDOUT:   File "C:\Program Files (x86)\OpenPype\3.14.10\dependencies\ftrack_api\session.py", line 1308, in commit
2025-02-21 15:00:38:  0: STDOUT:     result = self.call(batch)
2025-02-21 15:00:38:  0: STDOUT:   File "C:\Program Files (x86)\OpenPype\3.14.10\dependencies\ftrack_api\session.py", line 1687, in call
2025-02-21 15:00:38:  0: STDOUT:     raise ftrack_api.exception.ServerError(error_message)

This PR adds a specific function for the creation of these types of links and handles the existing of a previous link, removing it before creating the new one.