Support encryption context on Message #320

Job	Run time
Run unit tests for Python 3.14	2m 38s
Run unit tests for Python 3.10	2m 31s
Lint and check code	17s
Wheel ${{ matrix.image.name }} - Py ${{ matrix.python.version }} - ${{ matrix.cpu.platform }}	1s
Wheel MacOS Universal2 - Py ${{ matrix.py.version }}	1s
Check Completion	3s
Python ${{ matrix.python.version }} Wheel on Windows x64	1s
	5m 32s

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