Improve Error Handling

[Tom-McQuillan]

Three areas:
Configuring the client (client builder)
Configuring the request (request builder)
Transport Error (network transport error) lives on the request object

If the construction are invalid a null reference is returned. we can then call an error method to return an error string

[JamesWiresmith]

I need to see if I have a good open example for this (probably wiresmith/tedium) but check the error handling in the lv_interop crate. My standard has been to pass an error cluster as the first parameter and use the wrap_function to automatically convert between rust and LV errors

[jimkring]

@Tom-McQuillan I merged PR #44 with greatly improved error handling and messaging, including adding enumerated errors at a lower level and in the high-level API. Also included a Request.lvclass member VI that can be called to raise and error, if one exists for the request. The ClientBuilder and RequestBuilder also return some error information.

I'm going to close this issue. After you review, feel free to re-open this issue (or another, specific issue) if you feel there are some areas we can still improve.

[jimkring]

@Tom-McQuillan note that if you want to see this in action, you can look at the plugin for the HTTP Client Abstraction -- the "VI Tree" is actually a runable example and it uses the "raise error" VI shown below: