Add silent keep/discard inventory offer buttons

Adapted from Phoenix code

indra/newview/skins/default/xui/en-us/notifications.xml

@@ -6721,7 +6721,25 @@ An object named [OBJECTFROMNAME] owned by (an unknown user) has given you a [OBJ
    name="UserGiveItem"
    type="notify">
 [NAME] has given you a [OBJECTTYPE] named '[OBJECTNAME]'.
+
+(Keep)/(Discard) won't send an accepted/declined message.
     <form name="form">
+      <button
+       index="2"
+       name="Mute"
+       text="Mute"/>
+      <button
+       index="-1"
+       name="(Keep)"
+       text="(Keep)"/>
+      <button
+       index="-2"
+       name="(Discard)"
+       text="(Discard)"/>
+      <button
+       index="4"
+       name="Profile"
+       text="Profile"/>
       <button
        index="0"
        name="Keep"
@@ -6730,14 +6748,6 @@ An object named [OBJECTFROMNAME] owned by (an unknown user) has given you a [OBJ
        index="1"
        name="Discard"
        text="Discard"/>
-      <button
-       index="2"
-       name="Mute"
-       text="Mute"/>
-      <button
-       index="4"
-       name="Profile"
-       text="Profile"/>
     </form>
   </notification>