vdk-oracle: managed connection and queries

[antoniivanov]

We want to support managed connection against oracle database. That means that queries against oracle can be executed using any of VDK interfaces : vdk sql-query, job_input.execute_query, SQL steps and so on.

What needs to be done is

The https://github.com/vmware/versatile-data-kit/blob/feature/vdk-oracle/projects/vdk-plugins/vdk-oracle is already bootstrapped here. So it's a starting point.

1. Expose the configuration options needed for oracle. You can use the DuckDB as a reference example and add the definitions as here
2. Register the new connection type like this : https://github.com/vmware/versatile-data-kit/blob/main/projects/vdk-plugins/vdk-duckdb/src/vdk/plugin/duckdb/duckdb_plugin.py#L34
3. Write a function test that executes a data job with SQL steps and python step (job_input.execute_query) similarly to the way it was done here https://github.com/vmware/versatile-data-kit/blob/main/projects/vdk-plugins/vdk-duckdb/tests/test_plugin.py#L36 (ignore the ingestion part of the test. Those should have been split anyway)
4. Update the README.md of the plugin as appropriate.