[sddm-theme] Revert bad hack for spacing in action buttons and use a proper solution

Summary: Merge remote-tracking branch 'origin/Plasma/5.16'

Subscribers: plasma-devel

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D21321

sddm-theme/Main.qml

@@ -205,6 +205,10 @@ PlasmaCore.ColorScope {
                         enabled: sddm.canSuspend
                         visible: !inputPanel.keyboardActive
                     },
+                    Item { // spacer
+                        width: units.largeSpacing / 2
+                        height: width
+                    },
                     ActionButton {
                         iconSource: "system-reboot"
                         text: i18nd("plasma_lookandfeel_org.kde.lookandfeel","Restart")
@@ -212,6 +216,10 @@ PlasmaCore.ColorScope {
                         enabled: sddm.canReboot
                         visible: !inputPanel.keyboardActive
                     },
+                    Item { // spacer
+                        width: units.largeSpacing / 2
+                        height: width
+                    },
                     ActionButton {
                         iconSource: "system-shutdown"
                         text: i18nd("plasma_lookandfeel_org.kde.lookandfeel","Shut Down")
@@ -219,6 +227,10 @@ PlasmaCore.ColorScope {
                         enabled: sddm.canPowerOff
                         visible: !inputPanel.keyboardActive
                     },
+                    Item { // spacer
+                        width: units.largeSpacing / 2
+                        height: width
+                    },
                     ActionButton {
                         iconSource: "system-user-prompt"
                         text: i18ndc("plasma_lookandfeel_org.kde.lookandfeel", "For switching to a username and password prompt", "Other...")