allow override the Schema Creator by a consumer

[adrianiacobghiula]

Is your feature request related to a problem? Please describe. A consumer should be allowed to select / choose / override the default Schema. For example select to use https://github.com/hamba/avro and not github.com/linkedin/goavro/v2

Describe the solution you'd like Allow the consumer in Options to set a different function as SchemaCreator