Add minimal test for basic hackathon operations and enhance test utilities

- Introduced a new test module for hackathon-related functionality.
- Implemented a basic test for creating a hackathon using a mock repository.
- Enhanced the test utilities in `lib.rs` for better request handling and response extraction.
- Added a `ServiceClient` struct to facilitate HTTP requests in tests.
- Created a `RequestBuilder` to streamline building and sending requests with headers and JSON bodies.

imphnen-utils/src/query_list.rs

@@ -101,10 +101,9 @@ impl<'a> QueryListBuilder<'a> {
         // Bind parameters for both data and count queries.
         // It's assumed that the parameters are named consistently and applied to both.
         // The ListQueryBuilder already uses $search, $per_page, $start, $filter.
-        if let Some(search) = &self.meta.search {
-            if !search.is_empty() {
-                query_exec = query_exec.bind(("search", search.to_lowercase()));
-            }
+        if let Some(search) = &self.meta.search
+            && !search.is_empty() {
+            query_exec = query_exec.bind(("search", search.to_lowercase()));
         }
         if let Some(filter_val) = &self.meta.filter {
             query_exec = crate::bind_filter_value(query_exec, filter_val.clone());