MM-31711 - Implement cursor paging for threads (#16748)

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

model/client4.go

@@ -5794,8 +5794,11 @@ func (c *Client4) GetUserThreads(userId, teamId string, options GetUserThreadsOp
 	if options.Since != 0 {
 		v.Set("since", fmt.Sprintf("%d", options.Since))
 	}
-	if options.Page != 0 {
-		v.Set("page", fmt.Sprintf("%d", options.Page))
+	if options.Before != "" {
+		v.Set("before", options.Before)
+	}
+	if options.After != "" {
+		v.Set("after", options.After)
 	}
 	if options.PageSize != 0 {
 		v.Set("pageSize", fmt.Sprintf("%d", options.PageSize))