## About the changes
When stickiness was set to empty or undefined while updating a strategy
via API the stickiness would be lost.
This adds a validation step after creating a strategy, that updating
with the same data used to create the strategy yields the same result.
The main change was lifting the default logic from the store layer to
the service layer and adapting tests accordingly
We're migrating to ESM, which will allow us to import the latest
versions of our dependencies.
Co-Authored-By: Christopher Kolstad <chriswk@getunleash.io>
