Support partial resource initialization errors

[iwahbe]

This allows a provider to indicate that it tried to Create, Update or Read a resource but was not able atomically succeed, leaving the resource in a partially initialized state.

[iwahbe]

This is motivated by pulumi/pulumi-pulumiservice#84, which requires control over partial initialization.

[VenelinMartinov]

Looks sensible but I'm not familiar with pulumi-go-provider.

Does this code run before the provider implementation of Update, Create etc or does it wrap the provider implementation?

[iwahbe]

Does this code run before the provider implementation of Update, Create etc or does it wrap the provider implementation?

Providers based on infer doesn't implement global methods for Update, Create, etc. Instead resources each define their own version of these methods. This code wraps the resource level implementation.