* Fix mark_branch function in Graph class to properly handle visited vertices
* Refactor build_and_cache_graph_from_db function in utils.py to simplify code and remove unnecessary parameter
* Fix retrieval of graph from cache in retrieve_vertices_order function
* Fix possible_id type annotation in get_id_from_search_string function
* Refactor APIRequest class to improve variable naming and remove unnecessary underscore prefix in headers parameter
* Refactor buildVertices function in buildUtils.ts to improve code readability and remove unnecessary variable assignment
* Fix API endpoints in test_endpoints.py to use correct HTTP methods