feat: Expose LogicalType(s) for columns in QueryResult, fix #24

[ovr]

Hello!

Fix - https://github.com/duckdb/duckdb-node/issues/24

Thanks

[Maxxen]

Perhaps it would be better do something similar to the Columns method on statements instead of just returning the type id and name:

https://github.com/duckdb/duckdb-node/blob/2722553743f45dcc5394011288f98ef92cc1f7bf/src/statement.cpp#L588

if you were to use the TypeToObject function (feel free to move it) youd get the extra type info recursively so that you can determine e.g. the width of decimals or the member types of structs.