`chain-spec-builder`: cleanup (#2174)

This PR removes:
-  `New`, `Generate`, `Edit` commands,
- `kitchensink` dependency
from the `chain-spec-builder` util.

New `convert-to-raw`, `update-code` commands were added.

Additionally renames the `runtime` command (which was added in #1256) to
`create`.

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Co-authored-by: Sebastian Kunert <[email protected]>
Co-authored-by: Bastian Köcher <[email protected]>
Co-authored-by: command-bot <>