Better Error Handling and Logging

Summary

Better error handling (less exceptions, more error codes) and logging (for more detailed error handling and configuration issues).

Issue: https://gitlab.indiscale.com/caosdb/customers/lfpb/management/-/issues/390

See also the tests in caosdb-cppinttest!2 (merged)

Focus

• The TransactionStatus class represents the current status of a Transaction instance.
• The TransactionCode is a numeric representation of the status and intended for c-compatible error handling.
• Messages and Message classes handle the errors, warnings and info messages that come from the server.
• Logging: The logging can be configured via a json file. Otherwise the default configuration is in place.
• A lot of code was moved in order to comply with -pedantic flag. Don't waste your time

Test Environment

Unit tests should run as described in README_SETUP

Integration tests should run against a linkahead in the f-grpc branch

Check List for the Author

Please, prepare your MR for a review. Be sure to write a summary and a focus and create gitlab comments for the reviewer. They should guide the reviewer through the changes, explain your changes and also point out open questions. For further good practices have a look at our review guidelines

• All automated tests pass
• Reference related Issues
• Up-to-date CHANGELOG.md
• Annotations in code (Gitlab comments)
  • Intent of new code
  • Problems with old code
  • Why this implementation?

Check List for the Reviewer

• I understand the intent of this MR
• All automated tests pass
• Up-to-date CHANGELOG.md
• The test environment setup works and the intended behavior is reproducible in the test environment
• In-code documentation and comments are up-to-date.
• Check: Are there spezifications? Are they satisfied?

For further good practices have a look at our review guidelines.

test/test_configuration.cpp

@@ -21,7 +21,7 @@
  */
 #include "caosdb/configuration.h"  // for ConfigurationError, Configuration...
 #include "caosdb/exceptions.h"     // for ConfigurationError
-#include "caosdb/log_level.h"      // for CAOSDB_DEFAULT_LOG_LEVEL, CAOSDB_...
+#include "caosdb/log_level.h"      // for DEFAULT_LOG_LEVEL, CAOSDB_LOG_...
 #include "caosdb/logging.h"        // for ConsoleSinkConfiguration, Logging...
 #include "caosdb_test_utility.h"   // for EXPECT_THROW_MESSAGE, TEST_DATA_DIR
 #include <gtest/gtest-message.h>   // for Message
@@ -84,7 +84,7 @@ TEST_F(test_configuration, initialize_logging) {
     caosdb::logging::LoggingConfiguration(LOG_LEVEL_ALL);
   auto console_sink =
     std::make_shared<caosdb::logging::ConsoleSinkConfiguration>(
-      "console", CAOSDB_DEFAULT_LOG_LEVEL);
+      "console", DEFAULT_LOG_LEVEL);
   logging_configuration.AddSink(console_sink);
 
   initialize_logging(logging_configuration);