Add questions caching layer to improve dashboard performance after migration to MLv2 (#38425)

* Apply performance tweaks during dashboard editing

* Revert one change for tests

* Fix unit test

* reapply fix

* Try another improvement

* Revert "Adding cache stats to metabase.lib.cache"

This reverts commit dc32be74.

* Fix unit test

* More question caching

* Revert "Revert "Adding cache stats to metabase.lib.cache""

This reverts commit 4eea6a12.

* Cache questions

* Pass object

* Reuse questions

* Fix unit tests

* Fix unit tests

* Resolve conflicts

* Reuse questions in autowire

* fix typecheck

* json.stringify -> toString

* naming cleanup

* Support multi-series dashboards

* cleanup

* cleanup

* Fix typecheck

* Use only unique targets

* Address comments