Improve error handling on upload

[trygve-lie]

This improves error handling on multiple cases where an upload can cause an error. They are more or less as follow:

• The arguments on each handler method is now the first thing to be validated. In other words we fail fast on wrong URI params.
• If a filepath or mimetype does not validate when writing / reading / deleting a file, the validation will error and terminate the operation. This did not really work.
• If a uploaded file is not a .tar or .tar.gz file, the upload process will be terminated with a http status 415. This status code have been in our API doc, but this has not really been the returned status code returned in this situation.
• If a uploaded file is to large, the upload process will now be terminated with a http status 413. This is a new http status code not described in our API doc.
• If a uploaded file is valid but is borked or contain a file we can not handle or parse for some reason, the upload process will now be terminated with a http status 422. This is a new http status code not described in our API doc.
• There are also files which we are not able to detect the mime type of. These would previously not be given a mime type when written to a sink which causes some errors when serving it again. These are now given a default application/octet-stream mimetype.

This PR does also include the first proper tests of the handlers. Should pave the path to get these documented properly over time.

[digitalsadhu]

Nice!

[github-actions]

🎉 This PR is included in version 1.0.0 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀