Making avro_to_arrow::schema::to_arrow_schema public

[ameyc]

Which issue does this PR close?

Closes #12451

Rationale for this change

We need schema::to_arrow_schema to be able to use avro_to_arrow module in situations where we are deserializing avro from in memory buffers and not an avro file.

What changes are included in this PR?

Are these changes tested?

Are there any user-facing changes?

[alamb]

Makes sense to me -- thanks @ameyc

[alamb]

BTW if you want to make it more likely this doesn't get broken in a future refactor, it might be worth cooking up an example that shows how you are using the api (in datafusion-examples)

[alamb]

Thanks again @ameyc

[ameyc]

thanks @alamb i was looking into adding something to datafusion-examples but that involves making sure the apache-avro in datafusion-examples is the same version as the one in datafusion-core since it isn't re-exported. shall we add a test to core/src/datasource/avro_to_arrow/mod.rs that captures the interplay between the AvroReader and schema::to_arrow_schema instead?

[alamb]

thanks @alamb i was looking into adding something to datafusion-examples but that involves making sure the apache-avro in datafusion-examples is the same version as the one in datafusion-core since it isn't re-exported. shall we add a test to core/src/datasource/avro_to_arrow/mod.rs that captures the interplay between the AvroReader and schema::to_arrow_schema instead?

That would be fine too

Perhaps we should add a re-export of avro to datafusion-core to make downstream users life easier (make it easier to keep versions synced)