Load protector middleware doesn't follow other Redux store conventions

[tiberiuichim]

The location should be src/middleware/storeProtectLoadUtils.

https://github.com/plone/volto/blob/5f57b18156d4d4e42c7687fda6088fa1d44fff8f/src/store.js#L11-L15

It's just a regular middleware, no need to treat it differently.