Support getting encryption context on a message #999

Job	Run time
Formatting Check	1m 33s
Lint	28m 30s
Run unit tests	22m 21s
Build the Wireshark dissector (ubuntu-latest)	38s
Build CPP Client on Windows x86	22m 17s
Build CPP Client on Windows x64	27m 0s
Build with the C++20 standard	5m 23s
Build Alpine x86_64	15m 55s
Build Deb x86_64	11m 0s
Build RPM x86_64	11m 14s
Build CPP Client on macOS with static dependencies	7m 47s
Check Completion	0s
	2h 33m 38s

Provide feedback