feat(terraform): add CVK_OKTA_1 to ensure that 2FA is enabled for okta app sign on policy rule

[ThReinecke]

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PR Title

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feat(terraform): add CKV_AWS_123 to ensure that VPC Endpoint Service is configured for Manual Acceptance

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Description

Hi, I realised that currently there are no checks for setting up okta when using terraform (https://registry.terraform.io/providers/okta/okta/latest/docs). Tf is great when using okta as it automates the setup, but I believe there are a few things that could go wrong / the user should be aware of when creating okta resources with terraform.

The reason for this PR is that I would like to use something like this myself :) There is much more to be done and all of the okta checks should have nuances, but I believe this might be a good start.

New/Edited policies

new check: CVK_OKTA_1

Description

I believe having 2FA instead of 1FA for an okta app sign on policy rule should be an obvious check. The docs for this rule are here: https://registry.terraform.io/providers/okta/okta/latest/docs/resources/app_signon_policy_rule.

Fix

Using 2FA

Checklist:

• [x] My code follows the style guidelines of this project
• [x] I have performed a self-review of my own code
• [x] I have commented my code, particularly in hard-to-understand areas
• [x] I have made corresponding changes to the documentation
• [x] I have added tests that prove my feature, policy, or fix is effective and works
• [x] New and existing tests pass locally with my changes
• [x] Any dependent changes have been merged and published in downstream modules