Added

• Added the information classification level of the build to the --version output.
• The log level which is generally determined by the --log-level flag can now be set using the NRFUTIL_LOG environment variable. The flag value will be used instead of the environment variable value if both are present.
• Added support for a modifier argument. This is an argument starting with '+' which is normally written immediately after nrfutil and can be used to configure the behaviour. eg. nrfutil +internal search will use the internal package index if you set up a config file in ~/.nrfutil/config/nrfutil-core/config.json with the following contents:

{
  "modifiers": {
    "internal": {
      "package_index_url": "https://github.com/(user)/nrfutil-package-index"
    }
  }
}

Any entries under the modifiers key will be valid modifier arguments. You can only use one modifier argument at a time.