refactor(ASFF): create class

[jfagoagas]

Context

We are creating modular outputs for Prowler, now is the time for the AWS Security Finding Format.

Description

• Create the ASFF(Output) class.
• Add documentation for all the functions.
• Refactor the filter_security_hub_findings_per_region since now we don't need to recreate the ASFF findings, we've been doing it twice 🤦
• Adapt the tests.

License

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[sergargar]

Tested locally and it perfectly works!

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 74.09326% with 50 lines in your changes missing coverage. Please review.

Project coverage is 87.39%. Comparing base (2345a73) to head (c7e9264).

Files	Patch %	Lines
prowler/lib/outputs/asff/asff.py	85.91%	20 Missing :warning:
prowler/lib/outputs/file_descriptors.py	10.00%	18 Missing :warning:
prowler/__main__.py	0.00%	8 Missing :warning:
...ler/providers/aws/lib/security_hub/security_hub.py	78.94%	4 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #4368 +/- ## ========================================== - Coverage 87.56% 87.39% -0.17% ========================================== Files 852 851 -1 Lines 26592 26618 +26 ========================================== - Hits 23284 23262 -22 - Misses 3308 3356 +48 ```

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[pedrooot]

Now, batch_send_to_security_hub use _send_findings_to_security_hub passing the findings as a dict and the finding format in AWSSecurityFindingFormat. The real problem it's that resolve_security_hub_previous_findings pass the findings in dict function. I've made a "parse" in _send_findings_to_security_hub and depending the data structure it makes a different behaviour. This is not correct so I'll work on standardize all

[pedrooot]

The final approach it's that all the findings passed to _send_findings_to_security_hub are dict