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/UI/AboutWindow.cc

@@ -55,6 +55,7 @@ AboutWindow::LicenceLabel::LicenceLabel(QWidget *parent, const QString &url,
                                         const Qt::TextFormat format)
     : QTextEdit(parent)
 {
+    VIVY_LOG_CTOR() << "Creating label for licence '" << url << '\'';
     QFile content(url);
     if (!content.open(QIODevice::ReadOnly | QIODevice::Text))
         throw std::runtime_error("Failed to open file that should be accessible");
@@ -83,6 +84,7 @@ AboutWindow::AboutWindow(QWidget *parent) noexcept
     : QMainWindow(parent, Qt::Dialog)
     , panels(new QTabWidget)
 {
+    VIVY_LOG_CTOR() << "Creating the 'Vivy - About' window";
     setWindowIcon(QIcon(VIVY_ICON_APP));
     setWindowTitle("Vivy - About");