feat(gql-error): add GQLSTATUS finders (#1671)

* feat(gql-error): add GQLSTATUS finders

In some situations it might be needed to check if GQL error or any error in its GQL error chain has a specific GQLSTATUS.

This update adds 2 new methods to `Neo4jException` to make it easier:
- `boolean containsGqlStatus(String gqlStatus)`
- `Optional<Neo4jException> findByGqlStatus(String gqlStatus)`

* Improve name and documentation

* Shorten name

* Update documentation

* Fix article