[release/6.0] Add missing Evidence types to AcccessControl NETFramework Facade

[ericstj]

Fixes #99447

Description

The AccessControl assembly is missing type forwards for Evidence and EvidenceBase on .NETFramework.

Customer Impact

Cannot use Evidence or EvidenceBase from a netstandard2.0 library and run on .NETFramework.

At compile time will see:

CS7069 Reference to type 'Evidence' claims it is defined in 'System.Security.AccessControl', but it could not be found

At runtime will see:

System.TypeLoadException : Could not load type 'System.Security.Policy.Evidence' from assembly 'System.Security.AccessControl, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'.

Regression

Yes, from 5.0 packages. See issue for RCA.

Testing

Manual, customer scenario + API Compat.

Risk

Very small. Simply adding type-forwards to the existing assembly.

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[carlossanlop]

The staging branches are currently open. Can you please retarget the PR to 6.0-staging?

[carlossanlop]

LGTM. Pending retargeting to the staging branch.

[carlossanlop]

Approved by Tactics via email. Will make sure to include it in today's flow to base.