Use `GenerateResourceConfig` RPC to generate config instead of using the `tfadd` if the server support it

[magodo]

Since terraform v1.14.0, there will be a new RPC protocol GenerateResourceConfig that allows the provider to generate a precise config instead of using tfadd. We shall check whether the target provider supports that, if so, we use this new method, otherwise fallback to using tfadd.

This requires the support of the new interfaces in terraform-client-go.

This also requires to add a check on the terraform version (with tf mode), if less than v1.14.0, still using tfadd. Gradually, we shall deprecate tfadd if all the azure providers have supported the new RPC protocol.

Reference: hashicorp/terraform#37515