Undo ODBC deprecation and enable usage on non-Windows systems.

[LightBender]

This PR moves ODBC back to Phobos where it belongs. It also adds the appropriate type aliases for non-Windows systems removing the Windows only limitation.

Paris with: dlang/dmd#15560

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Testing this PR locally

If you don't have a local development environment setup, you can use Digger to test this PR:

dub run digger -- build "master + phobos#8804"