Add Azure Virtual Desktop (AVD) reporting support

[cse-gh]

Description

Adds a new Get-AbrAzDesktopVirtualization private function that documents Azure Virtual Desktop resources with four InfoLevel tiers:

InfoLevel	Content
1	Summary tables for host pools, application groups, workspaces, scaling plans
2	Per-host-pool detail sections with custom RDP properties, agent update config, session host tables with health check styling
3	Registration token info (expiry/status), per-application-group detail with published applications for RemoteApp groups, per-scaling-plan schedule breakdowns (ramp-up/peak/ramp-down/off-peak)
4	Per-session-host vertical detail sections (OS version, VM resource ID, update state/error, expanded health checks), active user sessions per host pool

Health Checks

• SessionHostHealth: Warning style when session host status is not "Available" or health checks report failures
• DrainMode: Info style when session host has AllowNewSession = false
• RegistrationExpiry: Warning style when registration token is expired
• NoSessionHosts: Bold WARNING paragraph when a host pool has zero session hosts
• HostPoolCapacity: Bold WARNING paragraph when total sessions >= max capacity across all hosts

Azure Cmdlets Used

• Get-AzWvdHostPool, Get-AzWvdSessionHost, Get-AzWvdUserSession
• Get-AzWvdApplicationGroup, Get-AzWvdApplication
• Get-AzWvdWorkspace, Get-AzWvdScalingPlan

Files Changed

1. New: Src/Private/Get-AbrAzDesktopVirtualization.ps1 — the AVD reporting function (~587 lines)
2. Modified: Src/Public/Invoke-AsBuiltReport.Microsoft.Azure.ps1 — added DesktopVirtualization to $DefaultSectionOrder and $SectionFunctionMap
3. Modified: AsBuiltReport.Microsoft.Azure.json — added DesktopVirtualization to SectionOrder, InfoLevel, and HealthCheck sections

Related Issue

New feature — no existing issue. Discussed with @tpcarman.

Motivation and Context

Azure Virtual Desktop is a significant Azure service not currently covered by the report. This addition provides comprehensive AVD documentation covering host pools, session hosts, application groups, workspaces, and scaling plans — consistent with the existing module patterns.

How Has This Been Tested?

• Tested against a production Azure subscription with ~20 session hosts across multiple host pools
• Validated all four InfoLevel tiers (1 through 4) produce correct HTML output
• Tested with mix of running and deallocated session hosts
• Tested with both Desktop and RemoteApp application group types
• Health check styling confirmed working for unavailable hosts and drain mode
• Tag display confirmed working with AVD's TrackedResourceTags type (uses .Keys and .AdditionalProperties[])

Requires Az.DesktopVirtualization module.

Types of changes

• New feature (non-breaking change which adds functionality)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the contributing documentation.

[tpcarman]

@cse-gh Thanks for this. It looks good. What's your comfort level for adding in language support for your function?

If you wish to add it then I will leave the PR open for the changes to be made. Or if you prefer, I can merge the PR and implement language support for you.

[cse-gh]

I can certainly give it a shot.

[cse-gh]

Updated pull request with language support.

Refactored Get-AbrAzDesktopVirtualization.ps1 to use $LocalizedData pattern
Added AVD strings to en-US and en-GB language files
Added new es-ES, fr-FR, de-DE language files (with AVD sections translated)