Add phpcr cleanup command

[wachterjohannes]

Q	A
Bug fix?	no yes
New feature?	yes
BC breaks?	no
Deprecations?	no
Fixed tickets	none
Related issues/PRs	replaces #7043
License	MIT
Documentation PR	sulu/sulu-docs#791

What's in this PR?

This PR add a new command sulu:phpcr:cleanup to cleanup the phpcr repository.

Why?

This is needed to keep the repository clean.

Example Usage

bin/console sulu:phpcr:cleanup --force

To Do

• Create a documentation PR
• Use also publish event and the live session to cleanup the live node
• Test with different languages, blocks and image_maps
• Test with audience-targeting and segmentation
• Refactor to use StreamOutput with a file handle
• Guard the node with:
  • Check the alias and if the structure manager has metadata for the alias (see https://github.com/mamazu/sulu/pull/2/files#diff-fd6471db309389445b7798ca7915fa5cd47010b1d91336a145f60e36276abb93R77-R80)
  • Check if language has a template
  • Ignore nodes which could not be persisted (and or published)
• Add summary of the cleanup (stats and ignored nodes) to the debug-file at the top
• Feedback from @mamazu

[mamazu]

🎉