Add support to avro_schema_generator for inline records

[neslinesli93]

Currently, when using avrogen along with its avro_schema_generator, if a schema uses an inline record, it is always extracted into its own, distinct schema. It would be awesome to be able to specify a custom field (similar to the pii one) called inline that when set to true in a record, it doesn't result in a distinct avro schema being created