message-edition: support "Esc" to cancel edition

Change-Id: I4be91f83fbe3ba7cb3617792c687acb938d3e10a
GitLab: #892

src/app/mainview/MainView.qml

@@ -625,7 +625,11 @@ Rectangle {
     Shortcut {
         sequence: "Escape"
         context: Qt.ApplicationShortcut
-        onActivated: layoutManager.popFullScreenItem()
+        onActivated: {
+            MessagesAdapter.replyToId = ""
+            MessagesAdapter.editId = ""
+            layoutManager.popFullScreenItem()
+        }
     }
 
     Shortcut {

src/app/mainview/components/ChatView.qml

@@ -292,14 +292,4 @@ Rectangle {
             }
         }
     }
-
-    Shortcut {
-        sequence: "Ctrl+Escape"
-        context: Qt.WindowShortcut
-        enabled: root.visible
-        onActivated: {
-            MessagesAdapter.replyToId = ""
-            MessagesAdapter.editId = ""
-        }
-    }
 }

src/app/mainview/components/KeyboardShortcutTable.qml

@@ -110,7 +110,7 @@ Window {
             description: qsTr("Edit last message")
         }
         ListElement {
-            shortcut: "Ctrl + Esc"
+            shortcut: "Esc"
             description: qsTr("Cancel message edition")
         }
     }