Support moto by allowing non-awaitable content

[akshara08]

Description of Change

PR adds a patch to endpoint.convert_to_response_dict such that it can work with moto while not changing the expected behavior of the method. Tests are added

Issue (#979)

The primary problem with moto integration is this method. There are 2 main issues with that method

1. It expects raw to have raw_headers just to convert the headers to lowercase.
2. Moto passes MockRawResponse which is not awaitable causing the breaks with lines containing await.

How to reproduce the error

# test_response.py

@pytest.fixture
def aws_credentials():
    """Mocked AWS Credentials for moto."""
    os.environ["AWS_ACCESS_KEY_ID"] = "testing"
    os.environ["AWS_SECRET_ACCESS_KEY"] = "testing"
    os.environ["AWS_SECURITY_TOKEN"] = "testing"
    os.environ["AWS_SESSION_TOKEN"] = "testing"


@pytest.fixture
def s3(aws_credentials):
    with mock_s3():
        conn = boto3.resource("s3")
        conn.create_bucket(Bucket='testbucket')
        yield conn


def test_moto(s3):
    for i in range(3):
        s3.Bucket('testbucket').put_object(
            Key=f'glob_{i}.txt', Body=f"test glob file {i}"
        )
    path = 's3://testbucket/glob_*.txt'
    fs = s3fs.S3FileSystem()
    files = fs.glob(path) # Fails 
    assert len(files) == 3

Resolution

It's a two part solution

1. The first part will be a addressed on moto repo by creating raw_headers (PR)
2. The second part of the problem can be addressed in this repo by only awaiting for awaitable objects.

Assumptions

1. Assigning non-awaitable objects to response_dict['body'] without await is not expected to break any current behavior

Alternative methods considered

I tried consolidating all the changes in just one repo (see: #1004) but it's not possible

Checklist for All Submissions

• I have added change info to CHANGES.rst
• If this is resolving an issue (needed so future developers can determine if change is still necessary and under what conditions) (can be provided via link to issue with these details):
  • Detailed description of issue
  • Alternative methods considered (if any)
  • How issue is being resolved
  • How issue can be reproduced
• (NA) If this is providing a new feature (can be provided via link to issue with these details):
  • Detailed description of new feature
  • Why needed
  • Alternatives methods considered (if any)

Checklist when updating botocore and/or aiohttp versions

• I have read and followed CONTRIBUTING.rst
• I have updated test_patches.py where/if appropriate (also check if no changes necessary)
• I have ensured that the awscli/boto3 versions match the updated botocore version

[akshara08]

@thehesiod This is a much smaller PR. This needs to be merged for this PR to work completely.

[thehesiod]

check out https://github.com/aio-libs/aiobotocore/blob/master/aiobotocore/_helpers.py#L13

[akshara08]

Thanks! Updated!

[akshara08]

Also, I just came across this comment from you. 🤕 Is this all fixable someplace else?

[akshara08]

Alright don't bother merging this: See comment. I'm gonna peace out for a bit and think about this