Adds Arrow Duration type support to arrow-avro reader and writer

[nathaniel-d-ef]

Which issue does this PR close?

• Part of Add Avro Support #4886

Rationale for this change

This change adds support for Arrow DataType::Duration to the arrow-avro crate. Previous versions of this code return a NotYetImplemented error encouraging users to manually cast to Interval(MonthDayNano). With this change, Duration will now be represented as a long, with a metadata value of arrowDurationType which corresponds to the TimeUnit. This retains the Arrow paradigm for Duration of clock time, rather than the Avro approach of calendar time. Because of this disconnect between the two specs, any attempt to map the value (e.g. seconds into days) would be lossy, as days and months can be of varying length.

What changes are included in this PR?

Expands the arrow-avro crate to handle Arrow Duration types with various TimeUnit variants (Second, Millisecond, Microsecond, Nanosecond). Includes:

• Additions in encoder/decoder to support Duration types.
• Updates to schema handling for duration-specific metadata.
• Comprehensive unit tests for reading and writing Duration types.

Are these changes tested?

Yes, existing tests are all passing, and tests have been added to validate the encoding and decoding of Duration.

Are there any user-facing changes?

• Crate is not yet public