feat: Reexport some uniffi types for type sharing in-between generated Python packages

Makefile

@@ -2,8 +2,10 @@
 
 # Start from clean env: Delete `.venv`, then `python3 -m venv .venv`
 # Pre-requisite: Python virtual environment is active (source .venv/bin/activate)
-build-python: release
-  python3 -m venv .venv
-  source .venv/bin/activate
-  python3 -m pip install -r requirements.txt
-  maturin develop
+
+build-python:
+	rm -rf c2pa/c2pa
+	python3 -m pip uninstall -y maturin
+	python3 -m pip uninstall -y uniffi
+	python3 -m pip install -r requirements.txt
+	maturin develop

c2pa/__init__.py

@@ -13,5 +13,6 @@
 
 from .c2pa_api import Reader, Builder, create_signer, create_remote_signer, sign_ps256
 from .c2pa import Error, SigningAlg, CallbackSigner, sdk_version, version
+from .c2pa.c2pa import _UniffiConverterTypeSigningAlg, _UniffiRustBuffer
 
-__all__ = ['Reader', 'Builder', 'CallbackSigner', 'create_signer', 'sign_ps256', 'Error', 'SigningAlg', 'sdk_version', 'version', 'create_remote_signer']
+__all__ = ['Reader', 'Builder', 'CallbackSigner', 'create_signer', 'sign_ps256', 'Error', 'SigningAlg', 'sdk_version', 'version', 'create_remote_signer', '_UniffiConverterTypeSigningAlg', '_UniffiRustBuffer']