"Close Description" tooltip should instead say "Back"

Summary:
BUG: 384912

Change back button 'stooltip to say "Back" instead of "Close Description"

Test Plan:
Tested in KDE Neon. Works:

{F3919685}

Reviewers: apol, #discover_software_store

Reviewed By: apol, #discover_software_store

Subscribers: plasma-devel

Tags: #plasma, #discover_software_store

Differential Revision: https://phabricator.kde.org/D7904

discover/qml/ApplicationPage.qml

@@ -97,7 +97,7 @@ DiscoverPage {
 
                     ToolButton {
                         iconName: "draw-arrow-back"
-                        tooltip: i18n("Close Description")
+                        tooltip: i18n("Back")
                         enabled: appInfo.sClose.enabled
                         onClicked: appInfo.sClose.activated()
                     }