feat(IAM): Add inline policies checks and improve custom policy checks

[puchy22]

Context

This PR is due to #3833

There are some checks related to custom policies that should be covered with inline policies too.

Description

Added new inline checks and changed custom checks to reuse functions inside new checks. The new checks are:

• [x] iam_policy_no_full_access_to_cloudtrail
• [x] iam_policy_no_full_access_to_kms
• [x] iam_policy_allows_privilege_escalation

License

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.