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;
-}