Better default error handling

[Narretz]

At the moment, createSmartQueryOptionsFunction and createMutation"swallow" errors when you don't define an onError function (which is usually done with the codegen plugin):

vue-apollo-smart-ops/src/mutation.ts

Lines 109 to 112 in ecf949e

	} catch (error) {
	const { onError, context } = params;
	const errorHandlerResult: ApolloErrorHandlerResultInterface | undefined =
	onError != null ? onError(error, app, context) : undefined;

I find this behavior quite unintuitive. I would expect the to return the plain error returned from the reuqests (usually an ApolloError), same as the normal vue-apollo smart query / mutation do. Especially since the errorHandleResultInterface seems very opinionated and doesn't match the standard vue-apollo behavior:

vue-apollo-smart-ops/src/mutation.ts

Lines 109 to 112 in ecf949e

	} catch (error) {
	const { onError, context } = params;
	const errorHandlerResult: ApolloErrorHandlerResultInterface | undefined =
	onError != null ? onError(error, app, context) : undefined;

If you want to use this library mostly for the benefit of having types for operation arguments, and results, it's not necessary to conform to a different error result.