TASK: Remove usages of `$node->subgraphIdentity->contentStreamId` in structure adjustments

[mhsdesign]

Solves partially: https://github.com/neos/neos-development-collection/issues/5043

1.) Remove now obsolete ProjectedNodeIterator and expose $contentGraph directly

$this->projectedNodeIterator->nodeAggregatesOfType has been rewritten to $this->contentGraph->findNodeAggregatesByType

The ProjectedNodeIterator was before https://github.com/neos/neos-development-collection/pull/5028 required to encapsulate findNodeAggregatesByType to only work on the live workspace.

2.) Remove calls to $node->subgraphIdentity->contentStreamId and ask the content stream id from the content graph like started via https://github.com/neos/neos-development-collection/pull/5002

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• [ ] Code follows the PSR-2 coding style
• [ ] Tests have been created, run and adjusted as needed
• [ ] The PR is created against the lowest maintained branch
• [ ] Reviewer - PR Title is brief but complete and starts with FEATURE|TASK|BUGFIX
• [ ] Reviewer - The first section explains the change briefly for change-logs
• [ ] Reviewer - Breaking Changes are marked with !!! and have upgrade-instructions