ENH: Add test for extended extern C interface

Integration tests for https://gitlab.indiscale.com/caosdb/customers/lfpb/management/-/issues/411 and caosdb-cpplib!8 (merged)

Use a server in f-grpc-dev for the integration tests (e.g. caosdb-deploy in f-grpc with empty profile).

conanfile.txt

 [requires]
-caosdb/0.0.12
+caosdb/0.0.11
 gtest/1.11.0
 
 [generators]