Do not reset the ORDERLABEL if division is a page

[BartChris]

fixes #5220
alternative: #6244
We should not reset the ORDERLABEL of a page during metadata preservation since this breaks the pagination when the ORDERLABEL is set to excluded.
While this fixes the pagination issue there are other potential problems. I did an alternative pull request which tries to adress them all:
#6244

[BartChris]

Although i did not yet notice any problems when not resetting the ORDERLABEL for pages (as done in this PR), we can also extend the original logic. The root cause of the linked issue is, that the necessary logic for setting the LABEL and ORDERLABEL (which are set to NULL in the beginning) is not called for hidden metatdata.

kitodo-production/Kitodo/src/main/java/org/kitodo/production/forms/createprocess/ProcessFieldedMetadata.java

Lines 681 to 683 in eded39f

	Pair<BiConsumer<Division<?>, String>, String> metsFieldValue = row.getStructureFieldValue();
	if (Objects.nonNull(metsFieldValue)) {
	metsFieldValue.getKey().accept(division, metsFieldValue.getValue());

To solve the issue at hand we could for hiddenMetadata call the setters directly to not lose the ORDERLABELs and therefor our pagination. We would by this also preserve hidden division LABEL's, which might be lost.

private void processHiddenMetadata() {
        for (Metadata metadatum : hiddenMetadata) {
            if (metadatum instanceof MetadataEntry) {
                MetadataEntry metadataEntry = (MetadataEntry) metadatum;
                String key = metadataEntry.getKey().toUpperCase();
                String value = metadataEntry.getValue();
                switch (key) {
                    case "LABEL":
                        division.setLabel(value);
                        break;
                    case "ORDERLABEL":
                        division.setOrderlabel(value);
                        break;
                    case "CONTENTIDS":
                        division.getContentIds().add(URI.create(value));
                        break;
                }
            }
        }
        metadata.addAll(hiddenMetadata);
    }

A more general remark: The necessary setters for the divisions of (non-hidden) metadata elements in the UI are called as a side effect of the (IMHO very complicated) BiConsumer logic, which does some transformations to the values from the tree, but mainly defines the setters for different division values, which are then applied. There may be a specific reason for using functional interfaces here, but I wonder if there might be opportunities to simplify the logic for better readability and maintainability.

[solth]

@BartChris Please rebase against current master to avoid failing builds caused by broken Selenium tests!

[henning-gerhardt]

I can not review this small change as I do not know how to archive the suggested change. As test code is not changed is showing me that there is not test code or tests are not affected by this change.

[BartChris]

Since #6244 is merged, this is not needed any more.