[TASK] Allow stdWrap on MM SOLR_RELATION cObject

[b3nkai]

What this pr does

Allow stdWrap on MM SOLR_RELATION cObject

How to test

Add a stdWrap on a MM relation (like sys_category):

plugin.tx_solr.index.queue { 
  pages { 
    myfield_stringM = SOLR_RELATION 
    myfield_stringM { 
      localField = myfield 
      stdWrap.dataWrap = before | after 
    }
  } 
}

Fixes: #3408

[dkd-kaehm]

@b3nkai
Thanks for fixing that issue.
We want integration test case[s] for that.
Would you like to try setup the fixture and integration test?

Rlated Issues: #3152, #2147, #2743

[b3nkai]

Hi !
This is a good idea but to be honest I'm not sure to find some time in the next weeks.
I keep that in my todo list but if someone could take care of it it would go faster :)

[dkd-kaehm]

This change brakes currently the simple relations:
See the build logs(available up to 2023.02.05):
https://github.com/TYPO3-Solr/ext-solr/actions/runs/4004683414/jobs/6874144860#step:12:112

1) ApacheSolrForTypo3\Solr\Tests\Integration\ContentObject\RelationTest::canFallbackToPagesTableIfPagesLanguageOverlayTCAHasNoDefinitionForLocalColumn with data set #0 ('solr_relation_can_fallback_to...ld.xml')
Can not fallback to table "pages" on non existent column configuration in TCA for table "pages_language_overlay".
Failed asserting that two strings are identical.
--- Expected
+++ Actual
@@ @@
-'Some Category'
+''

/home/runner/work/ext-solr/ext-solr/Tests/Integration/ContentObject/RelationTest.php:50

2) ApacheSolrForTypo3\Solr\Tests\Integration\ContentObject\RelationTest::canFallbackToPagesTableIfPagesLanguageOverlayTCAHasNoDefinitionForLocalColumn with data set #1 ('solr_relation_can_get_related...ca.xml')
Can not fallback to table "pages" on non existent column configuration in TCA for table "pages_language_overlay".
Failed asserting that two strings are identical.
--- Expected
+++ Actual
@@ @@
-'Some Category'
+''

/home/runner/work/ext-solr/ext-solr/Tests/Integration/ContentObject/RelationTest.php:50