dev input connector iterator (#853)

* implement InputIterator

* add tests for http input iterator

* make input connector callable to get the internal input iterator

* make timeout argument kw-only and increase readability

* move http input test and add confluent input tests

* add test for confluentkafka input iterator

* add Dummy Input and Json Input-Connectors + tests

* remove raising StopIteration and allow returning None event from input iterator + adapt tests

* add FileInput Connector + tests

* fix mypy issues

* fix mypy issues: ignore confluent_kafka module (missing stub)

* move tests to parent dir

* simplify tests, complete connector base.py + update gitignore

* fix .gitignore

* annotate missing types in inputs

* fix mypy issues

* fix further mypy issues

* Update logprep/ng/abc/input.py

Co-authored-by: kmeinerz <meinerzkai@gmail.com>

* Update logprep/ng/abc/input.py

Co-authored-by: kmeinerz <meinerzkai@gmail.com>

* Update logprep/ng/connector/confluent_kafka/input.py

Co-authored-by: kmeinerz <meinerzkai@gmail.com>

* Update tests/unit/ng/connector/test_json_input.py

Co-authored-by: kmeinerz <meinerzkai@gmail.com>

* add missing module docstrings

* Update tests/unit/ng/connector/test_confluent_kafka_input.py

Co-authored-by: kmeinerz <meinerzkai@gmail.com>

* Update tests/unit/ng/connector/test_http_input.py

Co-authored-by: kmeinerz <meinerzkai@gmail.com>

* remove duplicate test

* fix black issue

* fix tests / increase test coverage

---------

Co-authored-by: kmeinerz <meinerzkai@gmail.com>

Author: kaya-david

.gitignore

@@ -29,3 +29,4 @@ target
 wheelhouse
 requirements.*
 .mypy_cache
+/scripts/