[TASK] Use preAddModifyDocuments hook for pages

[christophlehmann]

What this pr does

It calls the hook preAddModifyDocuments also for pages and deprecates the hook indexPagePostProcessPageDocument

How to test

• Register Hook $GLOBALS['TYPO3_CONF_VARS']['EXTCONF']['solr']['IndexQueueIndexer']['preAddModifyDocuments']['TestPageIndexerDocumentsModifier'] = TestPageIndexerDocumentsModifier::class;
• Index a page
• See postProcessorField_stringS: postprocessed in the indexed document

Fixes: #2285

[christophlehmann]

The pipeline errors seem not related to my changes

[dkd-kaehm]

@christophlehmann The tests on main and release-11.5.x branches will fail until TYPO3 11 LTS is fully supported. Is that a breaking change and unsuited for EXT:solr 11.1.x and 11.0.x?

[christophlehmann]

@dkd-kaehm The change may lead to different behaviour in indexed documents when one uses the preAddModifyDocuments hook for records and (now for pages too).

[dkd-kaehm]

Damn, I lost this nice change for TYPO3 11 release.

Even if it's a BC, I still merge it in release-11.5.x, because this issue exists since years and users want it. The release note about this change want to be bolded and marked with !!!

[dkd-friedrich]

Unfortunately, we overlooked in this discussion that while preAddModifyDocuments does actually not work, there are 3 hooks that could be used:

$GLOBALS['TYPO3_CONF_VARS']['EXTCONF']['solr']['Indexer']['indexPagePostProcessPageDocument']
$GLOBALS['TYPO3_CONF_VARS']['EXTCONF']['solr']['Indexer']['indexPageSubstitutePageDocument']
$GLOBALS['TYPO3_CONF_VARS']['EXTCONF']['solr']['Indexer']['indexPageAddDocuments']

We plan to merge and simplify the hooks later, see #3441