[Compat] Don't generate error for non-data ExecuteReader queries

[MaceWindu]

Currently it generates There is no table in the server's response. error (e.g. for DML query like CREATE TABLE), which doesn't match behavior of other ADO.NET providers where they return empty data reader.

Real world example:

This behavior is not compatible with LINQPad raw SQL functionality as it use ExecuteReader API internally for all raw SQL queries:

• LINQPad shows error
• LINQPad treats exception as query failure (which is not true, as server executed query successfully) and doesn't apply success branch post-query logic (e.g. doesn't check that database schema changed and should be reloaded)

[MaceWindu]

BTW, this should useful for compat testing dotnet/runtime#17004 (comment)