feat(jmespath): add powertools functions

[dreamorosi]

Description of your changes

This PR is a follow up to #2259 and introduces a series of custom functions to the JMESPath utility which will allow customer to work with complex data types like JSON, base64, and gzip encoded fields.

These function match 1:1 the ones available in Powertools for AWS Lambda (Python) and are one of the key differentiator of the Powertools JMESPath utility versus other JMESPath libraries available on npm.

At the moment we support the following functions:

• powertools_json
• powertools_base64
• powertools_base64_gzip

Customers will be able to use them with AWS as well as own events. For example, when processing an event coming from API Gateway the body field will be JSON stringified and might be also base64-encoded.

Taking an example event like:

{
  "headers": [],
  "method": "GET",
  "body": "{\"foo\": 1}"
}

Without these functions the customer would be able to only use expressions like search(event, 'body'), but would have to handle the actual content of the body on their own.

With these functions they will be able to do things like search(event, 'powertools_json(body).foo') to select fields within the parsed body.

Related issues, RFCs

Issue number: #2207

Checklist

• My changes meet the tenets criteria
• I have performed a self-review of my own code
• I have commented my code where necessary, particularly in areas that should be flagged with a TODO, or hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my change is effective and works
• The PR title follows the conventional commit semantics

Breaking change checklist

Is it a breaking change?: NO

• I have documented the migration process
• I have added, implemented necessary warnings (if it can live side by side)

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[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
0.0% Duplication on New Code

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