community[minor]: add Neo4j Graph enhancedSchema option (#5413)

* Implement addGraphDocuments method for neo4j graph~

* Add integration tests for new method and make them pass.

* Revert back to int skipped, because remote db

* Fix Serializable extension

* Make metadata optional

* Linting

* Format

* Update extensions and props passing

* Format

* Add enhanced schema option.

* Format

* Update test

* Update test

* Format

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Co-authored-by: jacoblee93 <[email protected]>

Author: easwee