[CDF-25804] Add about command (#2251)

# Description

Adding a new command, `cdf about` to help users get an overview of their
current toolkit configuration and to simplify debugging configuration
problems, like `cdf.toml` being placed in the wrong working directory
and spelling mistakes in the TOML file itself.

Also deleted FeatureFlagsCommand and set alpha_flag for graphql=False,
not including this in the changelog since they are hidden components.

## Bump

- [x] Patch
- [ ] Skip

## Changelog

### Added

- Added the `cdf about` command to give an overview of current toolkit
configuration and simplify debugging issues.

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Co-authored-by: Magnus Schjølberg <magnus.schjolberg@cognitedata.com>
Co-authored-by: Anders Albert <60234212+doctrino@users.noreply.github.com>
