Pyrrowhead

- Removed all code running at install time. Pyrrowhead will no instead look for a
`~/.pyrrowhead` directory and initialize the directory if it doesn't exist.
- Added command `pyrrowhead cloud client-add` so client systems can be added to the
cloud config without having to edit it manually.
- All code is now formatted with Black.

- Now considered to be a beta release.
- Updated dependencies, installation should now work without issues.
- Restructured the repository to use an `src/` style.
- Remove option to choose default cloud installation directory during installation.

- System query is now supported when the System registry is present.
- Services can be inspected to get more information.
- Orchestration and authorization rules can be listed, added and removed in the same way services can.
- Setup and installation now set up the docker subnetwork and container ip addresses.
- Upon installation, the user will be asked where to install Arrowhead local clouds by default.