V14: Allow file uploads when save and publishing

[Zeegaan]

Notes

• There was a bug that did not allow us to save and publish a document, when you had uploaded a file to a file upload field.
• This was because the TemporaryFileUploadValidator would fail validation for the temporary file, as it would fail when contentSettings.IsFileAllowedForUpload(extension) was true, which is the wrong way around 🙈 This has been remedied by checking if its false instead 😛

How to test

• Create a document type, with a file upload property
• Try to create some content with that document type, make sure to upload an image (jpg for example)
• Save and publish, this should now no longer yield errors 😁

Image I used for testing: