Refact CopySupport._normalize_ids_after_copy for better STATE_NEW handling with activated workflow

[drfho]

On activated workflow copy/paste-inserted objects shall not be visible. That is why the get the status "NEW". If pageelements are inserted into a page, the current page-node shall get the status changed, and the new pagelements the status "NEW". If a document (tree) is inserted the inserted page-like objects shall get the status "NEW" to prevent them being published instantly. The pages subordinated pageelements are not set to "NEW" because

1. their page is "NEW" (=invisble) and thus their pagelements are not invisible
2. removing status "NEW" from all subordinated pageelements individually by changing/saving them to "MODIFIED" would be unproductive

Hint: This STATUS_NEW settting does not happen if the workflow is deaktivated; here the copied nodes are instantly visible.

Moreover the code change tries to add some Py best practices:

1. Avoid mutable default arguments.
2. Reduce code nesting for readability.
3. Use helper functions for repeated logic.
4. Follow PEP8 for indentation and naming.

The function normalize_ids_after_copy() gets 2. more parameter (is_initial_node=True, processed_nodes=None) to differ the recursion-case (tree-inserting) and avoid multiple onObjChange-events.

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References:

1. 7aaec72
2. normalize_ids_after_copy(): Avoid Repetitive Indexing and Collateral Renaming #404
3. https://github.com/idasm-unibe-ch/unibe-cms/pull/952#issuecomment-2909300928
4. https://github.com/sntl-projects/neon/issues/43

[zmsdev]

@drfho
I would suggest the following alternative with custom events for the copied/moved objects:
https://github.com/zms-publishing/ZMS/compare/fb_normalize_ids_after_copy?expand=1