Enhance bundle.read_config to pick either yaml or json automatically

https://github.com/Project-MONAI/model-zoo/tree/dev/models/pancreas_ct_dints_segmentation/configs vs https://github.com/Project-MONAI/model-zoo/tree/dev/models/spleen_ct_segmentation/configs

One using yaml and other using json.

If we want to use https://github.com/Project-MONAI/MONAI/blob/dev/monai/bundle/config_parser.py#L254 We have to pre-check if user is using yaml or json. This API can be abstracted to config without extension and def read_config can take care of loading based on what exists…

[wyli]

@SachidanandAlle for now we can do it with dict update:

from monai.bundle import ConfigParser

config = {
    "my_dims": 2,
    "dims_1": "$@my_dims + 1",
}
parser = ConfigParser(config)
parser.config.update({"my_dims": 3})
print(parser)
print(parser.get_parsed_content())

outputs:

{'my_dims': 3, 'dims_1': '$@my_dims + 1'}
{'my_dims': 3, 'dims_1': 4}

[SachidanandAlle]

Also it shall be great if you can support overrides as part of ConfigParser.read_config.
Currently it’s only supported through monai.bundle.run

For example: in some situations, the bundle_root kind of variables need override. https://github.com/Project-MONAI/model-zoo/blob/dev/models/pancreas_ct_dints_segmentation/configs/inference.yaml#L7-L9

Without run, if we want to get the instances in such cases, we need to pass some overrides for the config parser/reader.