feat(terraform): Add new checks for GCP and Azure

[ChananM]

Description

This PR introduces two new security checks to Checkov:

• GCP (CKV_GCP_99): Ensures that Google Cloud Memorystore for Redis instances are not publicly exposed.
• Azure (CKV_AZURE_101): Verifies that threat detection is enabled on Azure SQL databases.

These checks are based on modern security best practices and help prevent common misconfigurations.

New/Edited policies

GCP - CKV_GCP_99: Ensure Memorystore for Redis is not exposed to public internet

Description: This policy checks that Google Cloud Memorystore for Redis instances are not configured with connect_mode = "DIRECT_PEERING", which would expose them to the public internet. Exposing in-memory data stores to the public can lead to unauthorized access and data breaches.

Fix: Set the connect_mode to PRIVATE_SERVICE_ACCESS.

Azure - CKV_AZURE_101: Ensure that Threat Detection is enabled for SQL Database

Description: This policy ensures that Azure SQL databases have threat detection enabled. Threat detection is a critical security feature that identifies and alerts on potential security threats, such as SQL injection attacks.

Fix: Enable the threat_detection_policy on the azurerm_sql_database resource.

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my feature, policy, or fix is effective and works
• New and existing tests pass locally with my changes