[Cloud Posture] Rule template schema changes - introducing metadata field

[kfirpeled]

What does this PR do?

In version 8.4.0 we've refactored the schema of csp-rule-template and introduced a new metadata field to hold all the static information

Checklist

• I have reviewed tips for building integrations and this pull request is aligned with them.
• I have verified that all data streams collect metrics or logs.
• I have added an entry to my package's changelog.yml file.
• I have verified that Kibana version constraints are current according to guidelines.

Author's Checklist

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How to test this PR locally

Related issues

• [Cloud Posture] migrating rule and rule template SO static fields to metadata field kibana#134599

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• Start Time: 2022-06-28T15:58:02.991+0000

• Duration: 18 min 8 sec

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Name	Metrics % (covered/total)	Diff
Packages	100.0% (0/0)	💚
Files	100.0% (0/0)	💚 3.409
Classes	100.0% (0/0)	💚 3.409
Methods	33.333% (1/3)	👎 -55.487
Lines	100.0% (0/0)	💚 10.064
Conditionals	100.0% (0/0)	💚