Picodi

- Make `Dependency.__call__` async because FastAPI always runs Picodi deps in threadpool even if they are async
- Rename `Dependency` to `Depends` [internal change]
- Run mypy in tests directory
- Make sure that `inject` doesn't change type of wrapped function (e.g. coroutinefunction, generatorfunction, etc.)
- Added Starlette integration
- Added FastAPI integration
- Breaking changes:
- Return value of `Provide` no longer has `__call__` method

- Fixed bug with contextvars when `init_dependencies` run in different context
- Breaking changes:
- Changed default scope class of `init_dependencies` and `shutdown_dependencies` to `SingletonScope

- `ignore_manual_init` argument of `dependency` decorator now can be callable type

- Added `helpers.enter` context manager for resolving dependencies in pytest fixtures

- Fixed typehints
- Fixed rare error when `shutdown_dependencies` raises "RuntimeError: There is no current event loop"

- Updated docstrings