Change config files into folders with a file per service

Currently configs are made as one file per target, e.g. `bigbox-v1-cm.json`, this creates 2 issues:

1. Very large config files
2. Frequent merge conflicts when two branches change a common config

To fix both of these issues a config should now be a folder with a file per service. The config service and the capability used by the config service for config loading need to be edited for this change

先找出 config service 以及它用來載入 config 的 capability，接著追蹤 bigbox-v1-cm.json 等目標 config 檔案如何被發現及讀取。重構該載入路徑，使其支援包含每個 service 一個檔案的資料夾，並驗證大型 config 與並行的 service 變更不再需要共用檔案。

由索引模型根據 Issue 內容生成。