Use multi-part form to receive files to index on server

- This uses existing HTTP affordance to process files
  - Better handling of binary file formats as removes need to url encode/decode
  - Less memory utilization than streaming json as files get
    automatically written to disk once memory utilization exceeds preset limits
  - No manual parsing of raw files streams required

pyproject.toml

@@ -40,6 +40,7 @@ dependencies = [
     "dateparser >= 1.1.1",
     "defusedxml == 0.7.1",
     "fastapi == 0.77.1",
+    "python-multipart >= 0.0.5",
     "jinja2 == 3.1.2",
     "openai >= 0.27.0, < 1.0.0",
     "tiktoken >= 0.3.2",