cannot use tabs in extras file

[ssube]

Using a YAML parser for JSON was quick and easy, but the difference in whitespace requirements will be a nuisance:

[2023-05-01 16:38:17,199] ERROR: MainProcess MainThread onnx_web.server.load: error loading extras file
Traceback (most recent call last):
  File "onnx_web\server\load.py", line 165, in load_extras
  File "yaml\__init__.py", line 125, in safe_load
  File "yaml\__init__.py", line 81, in load
  File "yaml\constructor.py", line 49, in get_single_data
  File "yaml\composer.py", line 36, in get_single_node
  File "yaml\composer.py", line 55, in compose_document
  File "yaml\composer.py", line 84, in compose_node
  File "yaml\composer.py", line 133, in compose_mapping_node
  File "yaml\composer.py", line 82, in compose_node
  File "yaml\composer.py", line 110, in compose_sequence_node
  File "yaml\parser.py", line 98, in check_event
  File "yaml\parser.py", line 486, in parse_flow_sequence_entry
  File "yaml\scanner.py", line 116, in check_token
  File "yaml\scanner.py", line 258, in fetch_more_tokens
yaml.scanner.ScannerError: while scanning for the next token
found character '\t' that cannot start any token
  in "<unicode string>", line 18, column 1:
            {
    ^

Add a helper method to load .json files using a JSON parser and .yaml files using the YAML one.