Add library to convert cron to human readable

What does this MR do and why?

Add library to convert cron to human readable

• update policies list to convert cron to human readable

Why cRonstrue

I chose cRonstrue from prettycron for several reasons:

• it provides all the dependencies it needs in the package, where prettycron separetely requires the user to install momentjs and laterjs
• it is more active

Changelog: added

EE: true

Screenshots or screen recordings

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	a language that is supported
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How to set up and validate locally

1. Follow the scan execution creation snippet to create some scan execution policies
2. Navigate to Security & Compliance => Policies
3. Create a policies with various schedules
4. Verify the policy detail drawer in the policy list

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #339785 (closed)