[FEA] Limit symbol visibility in shared library

[jlowe]

Is your feature request related to a problem? Please describe.
Currently the native build exports all symbols in the shared library. We should only be exporting symbols that are part of our API to avoid non-API usage and accidental conflicts with dependencies pulled in with other shared libraries (e.g.: spdlog).

Describe the solution you'd like
We should be limiting symbols to those that are explicitly exported. See rapidsai/cudf#15982 for how RAPIDS is doing this in cudf.