Ensure error hooks are run when provider returns FlagResolutionDetails with error code

[federicobond]

Currently, in error situations, it's possible for providers to return FlagResolutionDetails objects with errors set, OR throw. However, the SDK only runs the error hooks when an error is thrown.

It should either be impossible to return an object indicating an error (we'd need a new type) or the SDK should check the returned object and run the error hooks if an error is indicated.

See

python-sdk/openfeature/client.py

Line 378 in 3f336b3

error_hooks(flag_type, hook_context, err, reversed_merged_hooks, hook_hints)