[Tests] Drive item views from a playback (#7819)

QtTesting's own `currentChanged` command aborts on a one-element row list, so
pqWidgetTestEventPlayer drives views itself:

- selectRow selects a row through the selection model, the whole row, without a
  mouse event
- clickRow left-clicks the centre of a cell, so the view's own handlers run
- doubleClickRow double-clicks it, for views whose double click acts

A tree addresses a row by the path of rows leading to it ("2/0" is the first
child of the third top-level row), and a click opens a collapsed path first.
Rows are model rows, so a filtered or sorted model counts the rows it shows.

Asserting what a command did needs QtTesting's check players, which the XML
source never reached: it marked every event an action, so `modelRowCount` was
rejected as unknown. An event now carries `type="check"` to be played as a
check.

Testing/item_view_test.xml drives the grouped settings navigation through
selectRow and clickRow and asserts the page stack followed.
Testing/deck_editor_double_click_test.xml proves the difference between the two
clicks: a single click on a card database row only selects it, a double click
adds the card to the deck.

Testing/deck_editor_double_click_test.xml

@@ -0,0 +1,34 @@
+<events>
+    <!--
+        A single click and a double click differ, and only a double click acts.
+
+        The card database view adds the card under the mouse to the deck on
+        double click (CardDatabaseView::actDoubleClick); a single click only
+        moves the current row and updates the preview. Asserting the deck's row
+        count after each proves the MouseButtonDblClick event really reaches the
+        view, which a page-index assertion in the settings tree cannot show.
+
+        The visual deck editor shows its cards in a picture grid, which is not an
+        item view, so the addressable list is the one in its card database dock.
+        Which card lands in the deck does not matter: the test asserts that a
+        click adds nothing and a double click adds one.
+
+        Assertions carry type="check": QtTesting only reaches its check players
+        with a check event.
+    -->
+    <event widget="MainWindow/tabSupervisor/stackedWidget/TabHome/homeWidget/homeActionsScrollArea/qt_scrollarea_viewport/homeButtonsBox/homeCreateNewDeckButton" command="activate" arguments="" />
+    <event widget="MainWindow" command="process_events" arguments="1500" />
+
+    <!-- A fresh deck starts empty -->
+    <event widget="MainWindow/tabSupervisor/stackedWidget/TabDeckEditorVisual/deckDock/deckDockContents/deckSplitter/deckListPane/deckView" command="modelRowCount" arguments="0" type="check" />
+
+    <!-- A single click only selects the card -->
+    <event widget="MainWindow/tabSupervisor/stackedWidget/TabDeckEditorVisual/databaseDisplayDock/databaseDisplayDockContents/databaseDisplayWidget/databaseView" command="clickRow" arguments="0" />
+    <event widget="MainWindow" command="process_events" arguments="300" />
+    <event widget="MainWindow/tabSupervisor/stackedWidget/TabDeckEditorVisual/deckDock/deckDockContents/deckSplitter/deckListPane/deckView" command="modelRowCount" arguments="0" type="check" />
+
+    <!-- A double click adds the card -->
+    <event widget="MainWindow/tabSupervisor/stackedWidget/TabDeckEditorVisual/databaseDisplayDock/databaseDisplayDockContents/databaseDisplayWidget/databaseView" command="doubleClickRow" arguments="0" />
+    <event widget="MainWindow" command="process_events" arguments="300" />
+    <event widget="MainWindow/tabSupervisor/stackedWidget/TabDeckEditorVisual/deckDock/deckDockContents/deckSplitter/deckListPane/deckView" command="modelRowCount" arguments="1" type="check" />
+</events>