**What**
- remove medusa-core-utils
- dispatch the utils where they belongs
- update usage
**NOTE**
I have been wondering if the graceful class should go into the utils package or medusa package, I ve put it in the medusa package as it seems to be the best place I can see for now and is tight to the server as well. Also, I wanted to avoid the utils package to depends on http and net dependencies, happy to change that if you feel like it
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