federation, handlers and integration added

src/pyfed/__init__.py

src/pyfed/cache/__init__.py

src/pyfed/cache/actor_cache.py

src/pyfed/cache/cache.py

src/pyfed/cache/memory_cache.py

src/pyfed/cache/nodeinfo_cache.py

src/pyfed/cache/webfinger_cache.py

src/pyfed/config.py

src/pyfed/content/__init__.py

src/pyfed/content/collections.py

src/pyfed/content/handler.py

src/pyfed/content/media.py

src/pyfed/federation/__init__.py

src/pyfed/federation/delivery.py

src/pyfed/federation/discovery.py

src/pyfed/federation/fetch.py

src/pyfed/federation/queue.py

src/pyfed/federation/rate_limit.py

src/pyfed/federation/resolver.py

src/pyfed/flow.drawio.png