feat: support resource based policies.

[Hweinstock]

Description

We want to support Resource Based Policies for AgentCore sources created via the CLI (that support it).

Acceptance Criteria

• customers are able to add resource based policies to runtime, gateway, and memory.
• implementation should be easy to extend to new resources and primitives when support is released.
• resource based policies should be configurable both directly in the CLI and the TUI wizard.

Additional Context

There is no CDK support for resource based policies ATM, so we need a solution for imperative calls.

[Hweinstock]

Note: this is blocked on missing CFN support.