[C++] Update proto files

[charlesbvll]

Describe the type of feature and its functionality.

The proto files listed in the CMakeLists.txt file for building the C++ SDK include recordset.proto, task.proto which no longer exist. It is also missing message.proto which is a dependency for other proto files.

Describe step by step what files and adjustments are you planning to include.

• Update CMakeLists.txtto list the correct proto files
• Update references to those proto files in src/
• Update serde functions to use the Message API instead of TaskIns/TaskRes (this is quite big)

Is there something else you want to add?

No response

[charlesbvll]

@uncleDecart I opened #5287, feel free to push to it (or to open PRs on the branch), I think the todo for switching to the Message API is quite a big topic, we could try to have a sync if you are interested in working on it

[uncleDecart]

@charlesbvll thank you very much! Would be great if you bring me up to speed. Shall I contact you on Slack to schedule the meeting?

[charlesbvll]

@uncleDecart Yes perfect!