Update v4 licensing infrastructure and security policy

[JimBobSquarePants]

Prerequisites

• I have written a descriptive pull-request title
• I have verified that there are no overlapping pull-requests open
• I have verified that I am following the existing coding patterns and practice as demonstrated in the repository. These follow strict Stylecop rules 👮.
• I have provided test coverage for my change (where applicable)

Description

Updates SharedInfrastructure to use Licensing 1.0.3 and copy the shared repository guidance and security policy. Includes the copied AGENTS.md and SECURITY.md changes.