This PR combines a ton of huge changes:
* Introduces a new `Field` mechanism for specifying data types and shapes. This new consistent mechanism is used for both VNode properties and cypher query responses.
* Uses the new Field mechanism to support strongly typed properties for VNodes. This also lets us introduce support for `BigInt` as well as a new `VDate` (calendar date) type.
* Actions no longer save their parameters into the DB (after all, parameters may change as the codebase evolves). Instead a complex trigger function is used to automatically capture and save a complete list of all the changes made by an action. Capturing the changes at the database level is much more robust and forwards-compatible, and allows us to simplify the implementation of actions considerably. There is now no need to manually specify how to "invert" an action, for example.
* Use [new `neo4j-driver-lite`](neo4j/neo4j-javascript-driver#692), which leaves out the Reactive API that we don't use.
* Upgrade Joi to the latest version

Notes:
* Unfortunately some weird bug in Neo4j is preventing the new trigger's custom error messages from being raised properly. So if you forget to include a modified VNode in the `modifiedNodes` list, or other common Action mistakes, you'll only get a very generic error: `Error executing triggers {trackActionChanges=Unable to complete transaction.}`. Hopefully the issue will be fixed in future Neo4j versions; I tried for a long time but wasn't able to find a workaround.
* Currently the new `UndoAction` will "soft delete" (change `:VNode` to `:DeletedVNode`) any newly created nodes. But if they have any fields with unique indexes, this could cause unexpected conflicts on the indexes of the deleted items, which are still in the database and still have their other labels. A simple solution could be to remove all labels except `:DeletedVNode` when deleting.

See merge request technotes.org/vertex-framework!12