feat: implement pagination for user retrieval and update feed fetching logic

thoughts-backend/models/src/schemas/pagination.rs

@@ -0,0 +1,12 @@
+use serde::Serialize;
+use utoipa::ToSchema;
+
+#[derive(Serialize, ToSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct PaginatedResponse<T> {
+    pub items: Vec<T>,
+    pub page: u64,
+    pub page_size: u64,
+    pub total_pages: u64,
+    pub total_items: u64,
+}