TableProviderFactories need to be async and return a Result to be useful

[avantgardnerio]

Is your feature request related to a problem or challenge? Please describe what you are trying to do.

In a previous PR, I added the concept of TableProviderFactorys, and added a test to show it was possible to do a CREATE EXTERNAL TABLE xxx STORED AS yyy. However, the test was a contrived scenario without the need for network access (as someone pointed out at the time). Real providers will need to do async network access and return an error if that fails.

Describe the solution you'd like

Update the trait signature to support resolution of the issues described above.

Describe alternatives you've considered

An entirely different approach where this is all static and compiled into the protocol and not extensible by third parties.