Added canary url and stepfunction monitoring with sns email and slack…

[bshien]

… integration

Description

Creates a Cloudwatch Synthetic Canary to monitor the metrics.opensearch.org url and monitors the step functions for failure. If either of these fail, a message will be published to SNS, and will send email and slack notifications.

Issues Resolved

https://github.com/opensearch-project/opensearch-metrics/issues/37

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[codecov[bot]]

Codecov Report

Attention: Patch coverage is 92.50000% with 12 lines in your changes missing coverage. Please review.

Project coverage is 76.64%. Comparing base (c0dbd62) to head (dc97672).

:exclamation: Current head dc97672 differs from pull request most recent head c597361

Please upload reports for the commit c597361 to get more accurate results.

Files	Patch %	Lines
...ava/org/opensearchmetrics/dagger/CommonModule.java	0.00%	5 Missing :warning:
...java/org/opensearchmetrics/lambda/SlackLambda.java	92.45%	3 Missing and 1 partial :warning:
...org/opensearchmetrics/util/SecretsManagerUtil.java	85.71%	2 Missing and 1 partial :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #40 +/- ## ============================================ + Coverage 73.49% 76.64% +3.15% - Complexity 163 174 +11 ============================================ Files 43 51 +8 Lines 962 1122 +160 Branches 47 50 +3 ============================================ + Hits 707 860 +153 - Misses 234 239 +5 - Partials 21 23 +2 ```

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[prudhvigodithi]

LGTM, thanks @bshien.