Enable and run integration tests

Currently there are no integration tests being run with the Swift implementation. This is something that we want to do in the future, and probably for a v1.0 of the implementation.

FYI: How we implemented this in apache/arrow-java: https://github.com/apache/arrow-java/blob/b459647910a6a373fb9f3d9cd0eb8cc717932bed/.github/workflows/test.yml#L149-L204