Implement Dictionary-encoded Layout

Implement read and write of the [Dictionary-encoded Layout](https://arrow.apache.org/docs/format/Columnar.html#dictionary-encoded-layout) and verify against integration tests.

Start with the Apache Arrow Dictionary-encoded Layout specification linked in the issue, then locate the Erlang read and write entry points and existing integration tests for related layouts. Done means dictionary-encoded data can be read and written and the integration tests verify compatibility.

Written by the indexing model from the issue text.