Move code in util package to _internal

There was just a single function `cancel_and_await` that was only for
internal use.

Signed-off-by: Sahas Subramanian <[email protected]>

Author: shsms

src/frequenz/sdk/util/asyncio.py src/frequenz/sdk/_internal/asyncio.pysrc/frequenz/sdk/util/asyncio.py renamed to src/frequenz/sdk/_internal/asyncio.py

@@ -11,8 +11,7 @@
 
 from frequenz.channels import Receiver, Sender
 
-from frequenz.sdk.util.asyncio import cancel_and_await
-
+from .._internal.asyncio import cancel_and_await
 from ..timeseries import Sample
 from ..timeseries._resampling import Resampler, ResamplerConfig, ResamplingError
 from ._channel_registry import ChannelRegistry

src/frequenz/sdk/actor/_resampling.py

@@ -17,7 +17,7 @@
 
 from frequenz.channels.util import Timer
 
-from ..util.asyncio import cancel_and_await
+from .._internal.asyncio import cancel_and_await
 from . import Sample
 
 _logger = logging.getLogger(__name__)

src/frequenz/sdk/timeseries/_resampling.py

@@ -17,7 +17,7 @@
 from frequenz.channels import Broadcast, Receiver
 from frequenz.channels._broadcast import Receiver as BroadcastReceiver
 
-from ...util.asyncio import cancel_and_await
+from ..._internal.asyncio import cancel_and_await
 from .. import Sample
 from ._formula_steps import (
     Adder,