Add documents

Add documents, document views and a document store to manage document and which one is displayed.

• The MainWindow make calls to the VivyDocumentStore to create the documents and the views
• The VivyDocumentStore create the documents
• The VivyDocumentView is only here to have a view, it won't hold any data
• The VivyDocument can be manipulated in any part of the code
• Widgets view the VivyDocument through the VivyDocumentView
• Add the VivyApplication that will hold the window and the non-graphic data
• The main window can get the currently selected main document

src/Document/AudioDocument.cc

+#include "AudioDocument.h"
+#include "../Utils.h"
+
+#include <QFileInfo>
+
+AudioDocument *
+AudioDocument::fromFile(const QString audioFilePath) noexcept
+{
+    QFileInfo file(audioFilePath);
+    const QString fileSuffix = file.suffix();
+    const bool fileIsValid =
+        Vivy::Utils::audioFileSuffix.contains(fileSuffix) || Vivy::Utils::videoFileSuffix.contains(fileSuffix);
+
+    if (!fileIsValid)
+        return nullptr;
+
+    AudioDocument *ret = new AudioDocument();
+    return ret;
+}
+
+AudioDocument::Type
+AudioDocument::getAudioType() const noexcept
+{
+    return fileType;
+}
+
+QString
+AudioDocument::getFilePath() const noexcept
+{
+    return filePath;
+}