Missing keys for file object in TextExtractorFormSettings

Problem/Motivation

If I save the Search API Attachments configuration form, Tika could not be reached and executed.

This appears, because the test file object is not being created correctly and therefor the file is not stored in the public files folder as a temporary file.

However, it worked on some of our systems without this change. But others did not. After I added the missing keys, which define the file object as a temporary file and set the filename, I was able to process the configuration form.

Steps to reproduce

Use the latest version from Search Api Attachments and try to save the configuration form.

Proposed resolution

Add the missing keys to the file object.

See attached patch.