Merge branch 'hotfix/#6861-zend-cache-depends-on-zend-serializer'

Close #6861
Add test for #4517,#3211
Fix #4517
Update tests from foreach to iterator
Add to check valid
Update tests for #4517
#6825 - minor CS fixes (removing unneeded parenthetical)
#6825 - adding missing `@group` annotations for newly introduced tests
Merge branch 'hotfix/#6825-zend-navigation-recursive-iterator-compatibility' into develop

Close #6825
Close #4517
Forward port #6825
Forward port #4517