feat: Handle Fn::If intrinsic for Alarms

[mgrandis]

Issue #, if available:
#1624

Description of changes:
Handles Fn::If in DeploymentPreference/Alarms where we would only allow a list before.

Description of how you validated changes:

• Unit tests
• E2E tests
• Deployed the resulting CFN template and verified the stack content
• Integration test

Checklist:

• Write/update tests
• make pr passes
• Update documentation
• Verify transformed template deploys and application functions as expected

Examples?

Please reach out in the comments, if you want to add an example. Examples will be
added to sam init through https://github.com/awslabs/aws-sam-cli-app-templates/

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

[codecov-io]

Codecov Report

Merging #1923 (382347a) into develop (afcb3d3) will increase coverage by 0.08%.
The diff coverage is 100.00%.

@@             Coverage Diff             @@
##           develop    #1923      +/-   ##
===========================================
+ Coverage    93.85%   93.94%   +0.08%     
===========================================
  Files           89       89              
  Lines         5890     5926      +36     
  Branches      1206     1212       +6     
===========================================
+ Hits          5528     5567      +39     
+ Misses         166      164       -2     
+ Partials       196      195       -1     

Impacted Files	Coverage Δ
samtranslator/model/function_policies.py	100.00% <100.00%> (ø)
samtranslator/model/intrinsics.py	97.29% <100.00%> (+0.07%)	⬆️
...el/preferences/deployment_preference_collection.py	93.26% <100.00%> (+1.70%)	⬆️
samtranslator/model/resource_policies.py	100.00% <100.00%> (ø)
samtranslator/translator/translator.py	98.52% <100.00%> (+0.06%)	⬆️
samtranslator/sdk/parameter.py	100.00% <0.00%> (ø)
samtranslator/translator/arn_generator.py	94.44% <0.00%> (+1.34%)	⬆️
samtranslator/translator/logical_id_generator.py	100.00% <0.00%> (+9.09%)	⬆️

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