[PJRT C API] Plumb plugin attributes from plugin to JAX python.
[PJRT C API] Plumb plugin attributes from plugin to JAX python.

Also add a method for the plugin to return an xla_version plugin attribute.

Currently jaxlib pins a TPU/GPU backend, and uses `xla_extension_version` for backend version. As we want to stop pinning TPU/GPU backend and allow pip install different backend separately, we need this `xla_version` for features that are not capture by PJRT C API version. `xla_extension_version` will still be used for API changes such as xla_client.py, or any XLA changes in jaxlib that are not part of plugins.
