Size storage helper function

I think it would be useful to allow us to set all the possible settings we can configure on a bucket via the dashboard, through a SQL policy.



We can do it to make a bucket public, and we can do it to restrict the file extensions through storage.extension(). The only thing we cannot do is the file size. It would make total sense to have a helper function called storage.size() or something.

This way we can complete the whole bucket policy via sql instead of having to manually set it on the dashboard.