* Move the test file share contents to tests/share
This way, it can be reused between tests.
* cvat-sdk: Fix creating tasks with non-local files
Forcing the `Content-Type` for the `upload_data` API call to
`multipart/form-data` does not work, because the current logic for
converting Python values to parts (`ApiClient._convert_body_to_post_params`)
does not encode them in a way that Django REST Framework can understand (it
JSON-encodes each part).
Fortunately, we don't actually need to do that, since when we create a task
with non-local files, we don't need to upload any files, and so we can just
post the original JSON, so do just that.
I couldn't add a test for the remote image case, because CVAT rejects all URLs
with non-public IP addressses. However, I did test this case manually.
Роман Донченко