Multiple schemas support

[StarProxima]

## 1.8.0
- Multiple scheme support
- Support for specifying nullable types via anyOf
- Add new config parameter `root_client_name`
- Add new config parameter `name`
- Add new config parameter `put_in_folder`
- Add new config parameter `squash_clients`
- Rename `root_interface` to `root_client`
- Rename `squish_clients` to `put_clients_in_folder`

• Added support for generating multiple schemes
• Added new parameters for convenient work with several schemes at once
• Update README
• Backward compatibility of renamed parameters is preserved.