go/adbc/driver/snowflake: GetObjects API doesn't return table constraints

`GetObjects` API for snowflake go driver doesn't return table constraints: https://github.com/apache/arrow-adbc/blob/cac2d836c0371f86add8de0fe6f3d90293c808b0/go/adbc/driver/snowflake/connection.go#L177 as a part of `TABLE_SCHEMA`. Reference implementation can be found for the BigQuery driver: https://github.com/apache/arrow-adbc/blob/cc0c4e9c01b1feb7c175b22f7cc1b0d019751745/csharp/src/Drivers/BigQuery/BigQueryConnection.cs#L526

The goal would be:

- Add table constraints implementation for `GetObjects` within `getObjectsTables` method
- Add tests in https://github.com/ryan-syed/arrow-adbc/blob/main/csharp/test/Drivers/Snowflake/DriverTests.cs to check if the table constraints are returned
- Add parsing of table constraints in https://github.com/apache/arrow-adbc/blob/main/csharp/test/Apache.Arrow.Adbc.Tests/Metadata/GetObjectsParser.cs

Start in go/adbc/driver/snowflake/connection.go at the getObjectsTables method and compare the BigQuery implementation linked in the issue. Review csharp/test/Drivers/Snowflake/DriverTests.cs and csharp/test/Apache.Arrow.Adbc.Tests/Metadata/GetObjectsParser.cs for the requested test and parsing coverage. Done means GetObjects returns table constraints and the tests verify them.

Written by the indexing model from the issue text.