Fix SampleType download permissions

[stuzart]

Sample type permissions don't include Download, as it is not a downloadable asset, yet it does have an associated template that can be downloaded. Currently, the template is only downloadable to those in the same project. This leads to a bug when following the option to create samples as a batch submissions.

There is no reason why the template should be blocked from anyone that can see the SampleType, so simply make the download permissions mirror those of the view permissions. Except for anonymous users, for whom it is never downloadable.

[stuzart]

slight change to make it non downloadable to anonymous users