Addon command-line arguments

Impacts all add-ons with a backend part.

Whenever an addon with a backend part is executed on the worker, several arguments are passed to it.
A downside of this workflow is, that any changes to them require adjustments to the addon, meaning a breaking change to occur.

To be more flexible, all arguments are now deprecated and will be provided as environment variables from now on:

An environment variable replacement for --info was not implemented. The argument contained arbitrary information about the addon as a deep nested dictionary.
If needed, please use ADDON_ID to request additional information directly from the application using the public API.

Please see the documentation for a full list of supported variables.

The aforementioned command-line arguments will be removed eventually.
Addons should consider this breaking change in a way that they will work with the arguments being present and after their removal.