Clarify Permissive-In / Strict-Out Naming Policy in Guidelines

[apiarya]

Microsoft API Guidelines needs an update to clarify the Permissive-In / Strict-Out naming policy for API request and response.

https://github.com/microsoft/api-guidelines/blob/vNext/graph/GuidelinesGraph.md#naming

Add a section under Naming Conventions Input/Output Handling
Recommend that APIs:

• Accept a broader range of inputs (e.g., case-insensitive, lenient formats)
• Emit consistent, canonical outputs (e.g., strict casing, normalized values)

Encourage documentation of canonical forms and accepted variants