Unique/global InterpreterContext that is Storage agnostic (has a reference to the DbmsHandler instead)
* InterpreterContext is no longer the owner of Storage
* New Database structure that handles Storage, Triggers, Streams
* Renamed SessinContextHandler to DbmsHandler and simplified the multi-tenant logic
* Added Gatekeeper and updated handlers to use it
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Co-authored-by: Gareth Lloyd <gareth.lloyd@memgraph.io>
