Refactor attachment handling system with enhanced UI (#12085)

* Renamed NewEntryAttachmentsDialog to EditEntryAttachmentsDialog for clarity.
* Introduced EditEntryAttachmentsDialog class to manage editing of existing attachments.
* Added functionality to preview attachments while editing them.
* Enhanced EntryAttachmentsModel with rowByKey method for better key management.
* Add image attachment support with zoom functionality.
* Add html and markdown detection.
* Improve button layout on the attachment section when editing an entry

tests/gui/attachments/TestImageAttachmentsView.cpp

@@ -0,0 +1,76 @@
+#include "TestImageAttachmentsView.h"
+
+#include <attachments/ImageAttachmentsView.h>
+
+#include <QBuffer>
+#include <QPixmap>
+#include <QSignalSpy>
+#include <QTest>
+#include <QWheelEvent>
+
+void TestImageAttachmentsView::initTestCase()
+{
+    m_view.reset(new ImageAttachmentsView());
+
+    // Generate the black rectange.
+    QImage image(1000, 1000, QImage::Format_RGB32);
+    image.fill(Qt::black);
+
+    auto scene = new QGraphicsScene();
+    scene->addPixmap(QPixmap::fromImage(image));
+
+    m_view->setScene(scene);
+    m_view->show();
+
+    QCoreApplication::processEvents();
+}
+
+void TestImageAttachmentsView::testEmitWheelEvent()
+{
+    QSignalSpy ctrlWheelEvent{m_view.data(), &ImageAttachmentsView::ctrlWheelEvent};
+
+    QPoint center = m_view->rect().center();
+
+    m_view->setFocus();
+
+    QWheelEvent event(center, // local pos
+                      m_view->mapToGlobal(center), // global pos
+                      QPoint(0, 0),
+                      QPoint(0, 120),
+                      Qt::NoButton,
+                      Qt::ControlModifier,
+                      Qt::ScrollBegin,
+                      false);
+
+    QCoreApplication::sendEvent(m_view->viewport(), &event);
+
+    QCOMPARE(ctrlWheelEvent.count(), 1);
+}
+
+void TestImageAttachmentsView::testEnableFit()
+{
+    m_view->enableAutoFitInView();
+    QVERIFY(m_view->isAutoFitInViewActivated());
+
+    const auto oldTransform = m_view->transform();
+
+    m_view->resize(m_view->size() + QSize(100, 100));
+
+    QCoreApplication::processEvents();
+
+    QVERIFY(m_view->transform() != oldTransform);
+}
+
+void TestImageAttachmentsView::testDisableFit()
+{
+    m_view->disableAutoFitInView();
+    QVERIFY(!m_view->isAutoFitInViewActivated());
+
+    const auto expectedTransform = m_view->transform();
+
+    m_view->resize(m_view->size() + QSize(100, 100));
+
+    QCoreApplication::processEvents();
+
+    QCOMPARE(m_view->transform(), expectedTransform);
+}