Readd Confluent Kafka drivers

[wbarnha]

Don't know why they were removed in a0fb224, let's bring it back!

[codecov-commenter]

Codecov Report

Patch coverage: 3.06% and project coverage change: -2.11% ⚠️

Comparison is base (b5db8a0) 93.72% compared to head (b2b448e) 91.62%.

❗ Current head b2b448e differs from pull request most recent head 5960fe1. Consider uploading reports for the commit 5960fe1 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #418      +/-   ##
==========================================
- Coverage   93.72%   91.62%   -2.11%     
==========================================
  Files         102      103       +1     
  Lines       11154    11388     +234     
  Branches     1534     1564      +30     
==========================================
- Hits        10454    10434      -20     
- Misses        612      867     +255     
+ Partials       88       87       -1     

Files Changed	Coverage Δ
faust/transport/drivers/confluent.py	0.00% <0.00%> (ø)
faust/transport/drivers/__init__.py	100.00% <100.00%> (+11.11%)	⬆️

... and 10 files with indirect coverage changes

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[wbarnha]

Tested things with the word_count example, still a long ways to go before this is in a functional state:

[2022-12-22 11:30:58,684] [10809] [INFO] [^---Recovery]: Starting... 
[2022-12-22 11:30:58,686] [10809] [INFO] [^---ConfluentConsumerThread]: Still waiting for assignment... 
[2022-12-22 11:30:59,687] [10809] [INFO] [^---ConfluentConsumerThread]: Still waiting for assignment... 
[2022-12-22 11:31:00,687] [10809] [INFO] [^---ConfluentConsumerThread]: Still waiting for assignment... 
[2022-12-22 11:31:01,687] [10809] [INFO] [^---ConfluentConsumerThread]: Still waiting for assignment... 
[2022-12-22 11:31:02,688] [10809] [INFO] [^---ConfluentConsumerThread]: Still waiting for assignment... 
[2022-12-22 11:31:03,688] [10809] [INFO] [^---ConfluentConsumerThread]: Still waiting for assignment... 
[2022-12-22 11:31:04,689] [10809] [INFO] [^---ConfluentConsumerThread]: Still waiting for assignment... 
[2022-12-22 11:31:05,689] [10809] [INFO] [^---ConfluentConsumerThread]: Still waiting for assignment... 
[2022-12-22 11:31:06,689] [10809] [INFO] [^---ConfluentConsumerThread]: Still waiting for assignment... 
[2022-12-22 11:31:07,690] [10809] [INFO] [^---ConfluentConsumerThread]: Still waiting for assignment... 
[2022-12-22 11:31:08,690] [10809] [INFO] [^---ConfluentConsumerThread]: Still waiting for assignment... 
[2022-12-22 11:31:09,691] [10809] [INFO] [^---ConfluentConsumerThread]: Still waiting for assignment... 
[2022-12-22 11:31:10,691] [10809] [INFO] [^---ConfluentConsumerThread]: Still waiting for assignment... 
[2022-12-22 11:31:11,691] [10809] [INFO] [^---ConfluentConsumerThread]: Still waiting for assignment... 
[2022-12-22 11:31:12,691] [10809] [INFO] [^---ConfluentConsumerThread]: Still waiting for assignment... 
[2022-12-22 11:31:13,692] [10809] [INFO] [^---ConfluentConsumerThread]: Still waiting for assignment... 
28535[2022-12-22 11:31:14,692] [10809] [ERROR] [^---Conductor]: Crashed reason=RuntimeError('This event loop is already running') 
Traceback (most recent call last):
  File "/home/redacted/PycharmProjects/faust/venv/lib/python3.8/site-packages/mode/services.py", line 843, in _execute_task
    await task
  File "/home/redacted/PycharmProjects/faust/faust/transport/conductor.py", line 293, in _subscriber
    await self.app.consumer.subscribe(await self._update_indices())
  File "/home/redacted/PycharmProjects/faust/faust/transport/consumer.py", line 1423, in subscribe
    await self._thread.subscribe(topics=topics)
  File "/home/redacted/PycharmProjects/faust/faust/transport/drivers/confluent.py", line 207, in subscribe
    self._ensure_consumer().poll(timeout=1)
  File "/home/redacted/PycharmProjects/faust/faust/transport/drivers/confluent.py", line 211, in _on_assign
    self.thread_loop.run_until_complete(
  File "/usr/lib/python3.8/asyncio/base_events.py", line 592, in run_until_complete
    self._check_running()
  File "/usr/lib/python3.8/asyncio/base_events.py", line 552, in _check_running
    raise RuntimeError('This event loop is already running')
RuntimeError: This event loop is already running

[wbarnha]

Keep an eye on confluentinc/confluent-kafka-python#1448, it would make more sense to use Confluent kafka in an asynchronous context.