Managed identities + Mermaid

[FreddyAyala]

This pull request introduces support for Managed Identities in the Azure Chat Solution Accelerator, enhancing security and simplifying management. It includes updates to documentation, infrastructure configuration, and deployment scripts.

Documentation Updates:

• docs/10.managed-identities.md: Added a comprehensive guide on using Managed Identities, outlining security advantages, services utilizing Managed Identities, and deployment instructions.

Infrastructure Configuration:

• infra/main.bicep: Introduced a new parameter disableLocalAuth to toggle Managed Identities, and propagated this parameter to the resources module. [1] [2]
• infra/main.json: Updated the Bicep template version, added new Azure regions, and introduced the disableLocalAuth parameter in multiple sections to support Managed Identities across various services. [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18]