Clarify what is "recent activity" in our room list ordering settings

As seen in the bug report, this setting is a bit confusing. First, it
refers to "message activity" but in reality it does take into account
all events. This is fine in my opinion, so I clarified that point.

Another thing is that it wasn't clear that timeline visibility settings
currently affect the sorting, so I added a tip about that.

Finally I wasn't happy with these two options being called "Activity"
so the old "Activity" setting is now called "Importance". The "Last
Message Activity" setting is now called "Newest Events".

BUG: 508480
FIXED-IN: 25.12.0

src/libneochat/enums/roomsortparameter.h

@@ -89,7 +89,7 @@ public:
         case Parameter::MostHighlights:
             return i18nc("@info", "Rooms with the most highlighted messages are higher");
         case Parameter::LastActive:
-            return i18nc("@info", "Rooms with the newer messages are higher");
+            return i18nc("@info", "Rooms with newer events are higher");
         default:
             return {};
         }

src/settings/NeoChatGeneralPage.qml

@@ -91,9 +91,15 @@ FormCard.FormCardPage {
         title: i18nc("@title:group", "Room List Sort Order")
     }
     FormCard.FormCard {
+        FormCard.FormTextDelegate {
+            text: i18nc("@info:label", "Hidden events are not considered as recent activity when sorting rooms.")
+        }
+
+        FormCard.FormDelegateSeparator {}
+
         FormCard.FormRadioDelegate {
-            text: i18nc("As in 'sort something based on last activity'", "Activity")
+            text: i18nc("As in 'sort something based on last activity'", "Importance")
-            description: i18nc("@info", "Rooms with unread notifications will be shown first")
+            description: i18nc("@info", "Rooms with unread notifications will be shown first.")
             checked: NeoChatConfig.sortOrder === 1
             enabled: !NeoChatConfig.isSortOrderImmutable
             onToggled: {
@@ -113,8 +119,8 @@ FormCard.FormCardPage {
             }
         }
         FormCard.FormRadioDelegate {
-            text: i18nc("As in 'sort something based on the last message'", "Last Message Activity")
+            text: i18nc("As in 'sort something based on the last event'", "Newest Events")
-            description: i18nc("@info", "Rooms with the newest activity will be shown first")
+            description: i18nc("@info", "Rooms with the newest events will be shown first.")
             checked: NeoChatConfig.sortOrder === 2
             enabled: !NeoChatConfig.isSortOrderImmutable
             onToggled: {