refactor: simplify notification messages for offer viewing

- Remove conditional notification logic in NewActivityView
- Remove redundant notification in RecentOffersToUserView and RecentOffersToUserProjectsView
- Standardize to single notification message format

src/views/RecentOffersToUserView.vue

@@ -138,7 +138,6 @@ export default class RecentOffersToUserView extends Vue {
         await this.$updateSettings({
           lastAckedOfferToUserJwtId: this.newOffersToUser[0].jwtId,
         });
-        this.notify.info("The offers are marked as viewed.", TIMEOUTS.LONG);
       }
 
       // eslint-disable-next-line @typescript-eslint/no-explicit-any