Add option to turn off adding of empty __init__.py files

[chrisirhc]

Summary

Improve compatibility in monorepo/Bazel usages, so that package path can be treated as native namespace packages

What is the feature request for?

The core library

The Problem

When using two proto files that have a similar prefix such as a.b.c and a.b.d, when these are produced as two separate artifacts consuming both of these as libraries would cause a import path collision since they both share __init__.py files in a and a/b folders.

The Ideal Solution

Add an option to skip creation of empty __init__.py files. Build tools treat the folders without __init__.py as namespace packages.

The Current Solution

I made the change as a patch and applied the patch on the library to get this capability. I can roll the change up as a PR if there's interest in this.

Related Solution

A similar option called legacy_create_init=False was introduced on bazel to solve this exact issue with package names. See https://rules-proto-grpc.com/en/latest/lang/python.html#python-grpc-compile:~:text=legacy_create_init%3DFalse .