Add clean logs support + dependent MR

Description

Add some mechanisms to add log support to Vivy.

• A LogSink is an object that will collect all the logs and emit them to a file, stderr, or in a Qt widget
• A Logger is the object used to create log message and submit them to the sink
• A LogMessage is a message, a line of log. You should not create it yourself, but use the macros or defined methods. They are submitted on destruction, so don't try things like auto msg = VIVY_LOG_WARN(appLog); msg << "toto"; unless you know what you are doing. If you don't pay attention, you might get log messages in a different order than what you originally wanted.

Example

Here is a small demo:

// Custom sink
VIVY_DCL_LOG_SINK(logSink) // Declare a Sink
std::shared_ptr<Logger> scriptLog = VIVY_GET_LOGGER(mySink, SCRIPT); // Custom logger
VIVY_LOG_WARN(scriptLog) << "This is" << ' ' << "very usefull!"; // Use the custom logger

// With the vivyApp's sink
class Object {
    // Add a logger to the sink and add log methods to the object
    VIVY_APP_LOGGABLE_OBJECT(Object, logger)

public:
    // ...
};

TODO List

• Create and use the API
• The simple stderr dispatcher
• The VivyConsoleDispatcher -> a dock widget with the MainWindow, like the console with VSCode or Eclipse
• Create the LogDispatcherThread -> flush at regular intervals the LogSink

Also merge dependent MR with this one to uniformize the logging process

src/Lib/Log.cc

@@ -5,8 +5,8 @@ namespace Vivy
 {
 LogSinkDispatcher::~LogSinkDispatcher() noexcept {}
 
-StderrLogSinkDispatcher::StderrLogSinkDispatcher(LogSink *const sink) noexcept
-    : LogSinkDispatcher(sink, std::string_view{ "stderr" })
+StderrLogSinkDispatcher::StderrLogSinkDispatcher() noexcept
+    : LogSinkDispatcher(std::string_view{ "stderr" })
 {
 }
 
@@ -14,14 +14,15 @@ void
 StderrLogSinkDispatcher::handleLogMessage(const std::string_view category,
                                           const LogMessage &msg) noexcept
 {
-    std::cerr << '[' << category << ']' << msg.getTextBuffer() << '\n';
+    std::cerr << '[' << category << "] " << msg.getTextBuffer() << '\n';
 }
 }
 
 // Vivy::LogSink implementation
 namespace Vivy
 {
-LogSink::~LogSink() noexcept {}
+// Flush all messages before exiting
+LogSink::~LogSink() noexcept { flush(); }
 
 // Get the log message from the logger and add it to the sink's queue.
 void
@@ -53,11 +54,11 @@ LogSink::newSink() noexcept
     return std::make_shared<makeSharedEnabler>();
 }
 
-// void
-// LogSink::registerLogDispatcher(std::shared_ptr<LogSinkDispatcher> dispatcher) noexcept
-// {
-//     logDispatchers.push_back(dispatcher);
-// }
+void
+LogSink::registerLogDispatcher(std::shared_ptr<LogSinkDispatcher> dispatcher) noexcept
+{
+    logDispatchers.push_back(dispatcher);
+}
 }
 
 // Vivy::Logger implementation
@@ -78,8 +79,6 @@ Logger::logEvent(const char *fileName, const char *functionName, const int lineN
                                                 .severity         = logSeverity,
                                                 .lineNumberInFile = lineNumber });
 }
-
-Logger::~Logger() noexcept {}
 }
 
 // Vivy::LogMessage implementation