* add: basic recommendations endpoint
* add: POST `/recommendations/models` recommendations endpoint
* add: get specific model endpoint
* add: DELETE `/recommendations/models/:id` and GET all models recommendations endpoint
* add: ONNX model upload endpoint
* add: save the file as a .tar.gz instead of ONNX
* add: verify_tar_gz function
* add: support for model upload
* add: PUT `/recommendations/model/:id` to update the model, name, collection
* refactor: recommendations -> personalization
* add: personalization tests
* add: personalization_model_manager_tests
* fix: review comments
* fix: review comments
