FE: Hide `Threat Monitoring` => `Policies` tab if `:security_orchestration_policies_configuration` feature flag is `true

Why are we doing this work

• before rolling out the :security_orchestration_policies_configuration feature flag, hide the Threat Monitoring => Policies tab behind the feature flag

Non-functional requirements

• Documentation:
• Testing:

Implementation plan

• frontend update the documentation for the policies sidebar
• frontend add a !window.gon.securityOrchestrationPoliciesConfiguration check on the Security & Compliance => Threat Monitoring Policies tab so that when the the Security & Compliance => Policies sidebar shows with the above completed work, the Policies tab is hidden because it will be fully replicated on the Policies sidebar