fix(files): fix file downloads

[hstievat]

Proposed changes

• Allows for downloading files from the files app, including directories as zip files.
• Before, the connection would timeout.

Brief description of rationale

When the response object was returned, the temporary file exited the context manager and closed itself automatically, creating a hidden error with the StreamingHttpResponse. By casting the FileWrapper to a list, the data is loaded into memory before the file is closed.

[coveralls]

coverage: 79.108% (-0.02%) from 79.123%
when pulling 2907535 on hstievat:files_fix
into 888a599 on tjcsl:dev.