bug: Fix zoom shortcuts

[DSCaskey]

This PR removes the keyboard shortcuts for zoom in and zoom out from the mainwindow.ui form. This should allow the code below to properly handle the key seq's for each OS.

QList<QKeySequence> zoomInShortcuts;
zoomInShortcuts.append(QKeySequence(QKeySequence::ZoomIn));
zoomInShortcuts.append(QKeySequence(Qt::ControlModifier + Qt::Key_Plus + Qt::KeypadModifier));
ui->zoomIn_Action->setShortcuts(zoomInShortcuts);
connect(ui->zoomIn_Action, &QAction::triggered, ui->view, &VMainGraphicsView::zoomIn);

QList<QKeySequence> zoomOutShortcuts;
zoomOutShortcuts.append(QKeySequence(QKeySequence::ZoomOut));
zoomOutShortcuts.append(QKeySequence(Qt::ControlModifier + Qt::Key_Minus + Qt::KeypadModifier));
ui->zoomOut_Action->setShortcuts(zoomOutShortcuts);
connect(ui->zoomOut_Action, &QAction::triggered, ui->view, &VMainGraphicsView::zoomOut);

Closes issue #1176