feat: Optimize Immer performance where possible, introduce `setUseStrictIteration` (#1164)

* Use WeakMap caching implementation of isPlainObject

* Add some early returns to `finalizeProperty`

* Add `strictIteration` option

* Add non-strict iteration handling

* Use strict iteration option

* Switch back to default strict iteration

* Fix strict iteration checks

* Shorten benchmark array sizes for faster results

* Dedupe Map/Set method overrides

* Removed old isPlainObject impl

* Add early bailout to `isFrozen`