Add searches for Cloudwatch Log Insights

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CloudWatch Logs Insights is an AWS feature introduced in 2018 that makes it possible to search and analyze CloudWatch log data over chosen time periods using a specialized query language.

Add relevant search queries to the serverless stack template (as in aws-samples/cloudwatch-logs-insights-queries) so they are then available as default queries in the console.

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As an aside, a more comprehensive and flexible but also expensive and technically heavy solution for indexing and searching logs is to hand the logs over to OpenSearch (Amazon's fork of the legendary Elasticsearch distributed full-text search and analytics engine), but as the article explains, it is not a pure serverless solution and will incur expenses for persistent computing resources and require more operational expertise on the backend team.

This may be something to keep in mind and to consider in the future.