Add SNS Action for Spidermon Notifications

[felipdc]

Summary:

This pull request introduces a new action that allows Spidermon to send notifications via AWS Simple Notification Service (SNS). This provides users with an alternative way to receive notifications and integrate Spidermon with other AWS services or third-party applications through SNS.

Changes:

• Added SendSNSNotification class to handle SNS notifications.
• Provided documentation on how to set up and use the SNS action.

Benefits:

• Offers more flexibility for users who are heavily invested in the AWS ecosystem.
• Allows for easy integration with other AWS services like Lambda, SQS, etc., by leveraging SNS topics.

How to Test:

1. Set up AWS credentials and an SNS topic as described in the documentation.
2. Configure Spidermon to use the new SNS action.
3. Trigger a Spidermon notification to see it being sent to the specified SNS topic.

Looking forward to feedback and any additional changes required.

[codecov]

Codecov Report

Patch coverage: 95.74% and project coverage change: +0.24% 🎉

Comparison is base (0cbb563) 79.14% compared to head (3ddfc2a) 79.39%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #413      +/-   ##
==========================================
+ Coverage   79.14%   79.39%   +0.24%     
==========================================
  Files          74       76       +2     
  Lines        3175     3222      +47     
  Branches      530      534       +4     
==========================================
+ Hits         2513     2558      +45     
- Misses        591      593       +2     
  Partials       71       71              

Files Changed	Coverage Δ
spidermon/contrib/actions/sns/__init__.py	94.44% <94.44%> (ø)
spidermon/contrib/actions/sns/notifiers.py	100.00% <100.00%> (ø)

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[rennerocha]

thought This is not related to this PR specifically, but maybe it would be nice, if we move any action that it is AWS related to a aws module. This would keep the code more organized and easier to locate.

So we could have:

spidermon/contrib/actions/aws/__init__.py
spidermon/contrib/actions/aws/sns.py
spidermon/contrib/actions/aws/ses.py  # for Amazon SES email

Maybe we could discuss this in a separate issue anyway.

[VMRuiz]

LGTM