superadmin mode does not work for extractors

[ocaisa]

Describe the bug
I wanted to submit a file for extraction in a space where I did not have rights. After enabling superadmin mode I could do the submission and saw that the extraction succeeded, but the upload of previews and metadata failed. @lmarini pointed out that extractions are always run under user privilieges, so this is an unintended abuse of superadmin.

To Reproduce
Steps to reproduce the behavior:

1. Enable superadmin mode in a space where you only have read rights
2. Submit something for extraction
3. Watch the logs for the extractor when it comes to metadata/preview upload, you will see 401 errors.

Expected behavior
I'm not sure I expect a change in behaviour, but if I did it would be restricting the capabilities of superadmin in the interface to those that it can actually fully use.

[ocaisa]

I'm fine if this is closed, I just wanted to put it here for the sake of documentation

[Albertagamergod1]

I'm fine if this is closed, I just wanted to put it here for the sake of documentation

Please find the fix for me