Node versioning system

Since nodes are constantly changing, we currently have to run automated upgrade scripts to replace node internals with the current version, update inputs, etc. A non destructive node versioning system similar to Crates is necessary for compatibility and ease of use.

Each instance of a node will store its version, and the document node definition will also store the version. The definition version will be incremented every time a node is changed, and every time a new version is created an upgrade script can be included to upgrade from the previous version to that version.

When the editor notices an out of date node, it prompts the user to upgrade it. It will use the mapping of version to upgrade scripts one by one to get the node to the most up to date version. The important part is that a node will never be automatically changed unless a user explicitly requests it. An ignore box should also be available, which dereferences the users node from the node definition.

Note that this is not related to editor structs and fields. That will still require breaking changes or best attempts at upgrading.

No files, tests, or entry points are named. Begin by locating the node-definition and editor code, then trace how node instances and document definitions are stored; the work is done when versioned definitions, sequential upgrade scripts, explicit upgrade prompts, and an ignore option are supported without automatic changes.

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