ENH: Test insert/update/delete and files in Extern C

Integration tests for https://gitlab.indiscale.com/caosdb/customers/lfpb/management/-/issues/412 and caosdb-cpplib!15 (merged)

test/CMakeLists.txt

@@ -24,6 +24,7 @@
 set(test_cases
     test_connection
     test_transaction
+	#test_file_transmission TODO add once fixed
     test_ccaosdb
     )