Restructuring the Repo to make it clear the difference between classic autogpt and the autogpt platform:
* Move the "classic" projects `autogpt`, `forge`, `frontend`, and `benchmark` into a `classic` folder
* Also rename `autogpt` to `original_autogpt` for absolute clarity
* Rename `rnd/` to `autogpt_platform/`
* `rnd/autogpt_builder` -> `autogpt_platform/frontend`
* `rnd/autogpt_server` -> `autogpt_platform/backend`
* Adjust any paths accordingly
