test(chunk-upload): Test chunk upload with many chunks (#2275)

Add a test that verifies that chunk uploading works as expected for an
upload which requires many (500+) chunks, split accross multiple (10)
requests. This test also verifies that the chunk uploading code works
for smaller chunks, since the way we achieve simulating a many-chunk
upload without requiring a very large file to upload is by reducing the
chunk size (in this case to 2 KiB).

ref #2194

Author: szokeasaurusrex