…ocessor.is` override (#2182)

* Validate state tree instances instead of snapshots in the SnapshotProcessor.is override

This fixes a bug where within `.is` on models with snapshot processors, we validated against the model snapshot, instead of the model node when given a node. This means that two different models with compatible snapshots would not `.is` instances of each other normally, but once a snapshot processor is added, they would. This adds a failing test capturing this case.

The PR that introduced this behaviour of validating the snapshot was introduced here: #1495, and I think was actually targeting a different use case -- passing *snapshots* to `.is`, not passing instances. The behaviour that PR added was to validate against the __processed__ version of a snapshot if passed a snapshot, which this PR maintains. But, if passed an instance, that PR elected to snapshot it as well, which I don't think is necessary, and breaks the substitutability of snapshot processed instances with their unwrapped counterparts.

* docs: bump JSdocon snapshotProcessor is

* docs: one more link for snapshotProcessor

* chore: version bump to 7.0.0-pre.1

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Co-authored-by: Tyler Scott Williams <tyler@coolsoftware.dev>

* Update tsconfig to typecheck tests

* Add missing @types/jest to package.json

* fix: TS failures in test files missing bun:test imports

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Co-authored-by: Tyler Williams <tyler@coolsoftware.dev>

* Fix docs with incorrect pre/post process functions

* Ensure bun.lockb up-to-date with latest HEAD

* Fix typings for snapshot processors

* chore: update bun:test import for `describe`

* Use SnapshotIn vs explicit type for snapshot processor test

* chore: update import

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Co-authored-by: Tyler Williams <tyler@coolsoftware.dev>

* Add model instantion test to exercise all property types

* Type create/validate to accept an instance type