:rocket: Stable types/experimental API in preparation for 0.1.0

[daquintero]

This PR contains:

• [X] A stable experimental API
• [x] Stable notebooks tested in a flake.nix
• [x] Add basic virtuoso support
• [x] Peform some data types renaming.
• [ ] Fully tested functionality except for anything that will change

The goal is to have piel tested enough so that any changes on the API won't affect any repos where piel is used.

[daquintero]

Awaiting for https://github.com/gdsfactory/gdsfactory7/issues/23 for a release

[daquintero]

Since many aspects will change between 0.1 and 0.2 and now that we're running all examples as part of the nix CI kind of inclined to continue with the release and iterate accordingly.

[daquintero]

Preparing for handover of development to the gdsfactory team