feat: Make DataFrame and Spec clients compatible with SystemLink Client http configuration

[santhoshramaraj]

• This contribution adheres to CONTRIBUTING.md.

What does this Pull Request accomplish?

Add JupyterHttpConfiguration as a fallback configuration for the HttpConfigurationManager. Allows the Clients to authenticate agnostic of the environment they're run from.

Why should this Pull Request be merged?

Enables SystemLink clients to adapt to supported run environments when using the default value for configuration arg like client = DataFrameClient()

What testing has been done?

Manual testing

• Run https://github.com/ni/nisystemlink-clients-python/blob/master/examples/dataframe/export_data.py on the computer with SystemLink Client connected with an SLE server
• KeyError occurs because JupyterHttpConfiguration is not available outside SLE
• Update the DataFrameClient() to use core.HttpConfigurationManager.get_configuration() as the default configuration
• Run the example, now, there should be no KeyError signifying that the client was created using the SystemLink client's HTTP Credentials

[mure]

Thanks for doing this!