feat: add support of Kinesis EFO Consumers

[jbleduigou]

Problem

So far EFO consumers were note shown in the inventory.
It could make sense to show them, because each EFO consumer incurs additional charges.

Solution

Use the ListStreamConsumers method provide by AWS to least the consumers for each Kinesis Data Stream.

Changes Made

• Modified streams.go so that EFO consumers are retrieved.
• Added unit tests with 100% coverage on the new code added.
• Added a mock for Kinesis Client to be used in unit tests
• Updated the IAM policy so that kinesis:ListStreamConsumers is allowed
• Updated the list of supported resources in the documentation

How to Test

In order to test the changes you first need to create a Kinesis Data Stream.
Then you need to register an EFO consumer, for instance using the AWS cli:
aws kinesis register-stream-consumer --stream-arn arn:aws:kinesis:us-east-1:0123456789:stream/my-awesome-data-stream --consumer-name my-awesome-efo-consumer

Screenshots

Checklist

• Code follows the contributing guidelines
• Changes have been thoroughly tested
• Documentation has been updated, if necessary
• Any dependencies have been added to the project, if necessary

Reviewers

@mlabouardy
@jakepage91

[AvineshTripathi]

Can we also add cost calutations too here so that we would not need to revisit this again? cc @Azanul

[jbleduigou]

Can we also add cost calutations too here so that we would not need to revisit this again? cc @Azanul

I was thinking of doing it in a separate PR.
Would that be ok?

[Azanul]

Can we also add cost calutations too here so that we would not need to revisit this again? cc @Azanul

I was thinking of doing it in a separate PR. Would that be ok?

That's fine but why do something in two steps if you can do in one, unless you've a stepcounter. It's fine either way.