Feat: AWS S3 file module

[PierreBeucher]

Encountering this bug on real S3:

Caused by:
    0: Failed to load environment.
    1: Couldn't resolve variable input VariableInput { name: "S3_OBJECT_AS_VAR", value: AwsS3ObjectInput(AwsS3ObjectInput { aws_s3_object: AwsS3Object { bucket: "novops-test-bucket", key: "test", region: None } }) }
    2: Couldn't get S3 object 'novops-test-bucket/test'
    3: service error
    4: unhandled error (PermanentRedirect)
    5: Error { code: "PermanentRedirect", message: "The bucket you are attempting to access must be addressed using the specified endpoint. Please send all future requests to this endpoint.", aws_request_id: "xxxx" .... }

Checking if a region parameter might be needed or if code check would suffice to use proper region (or if something else)

Probably related to https://github.com/awslabs/aws-sdk-rust/issues/183

[PierreBeucher]

Added region flag