Change ManagementGroupId from required to optional in both
deployment.ps1 and start-remediation.ps1. When not specified,
the scripts resolve the tenant root management group ID
automatically via (Get-AzContext).Tenant.Id.

Changes:
- deployment.ps1: ManagementGroupId parameter now Mandatory=false;
  auto-resolves to tenant root group with informational output
- start-remediation.ps1: same parameter change and auto-resolve
- README.md: updated both parameter tables (Required=No, default
  shown as 'Tenant root group'); simplified examples to omit
  ManagementGroupId where the default suffices; added explicit
  management group examples for users who need a custom scope

Remove hardcoded license type references from policy displayName
and description. The actual target license type is controlled by
parameters at assignment time, so the definition metadata should
not imply a specific value.

Changes:
- azurepolicy.json: displayName and description now use generic
  'Configure Arc-enabled SQL Server license type' wording
- deployment.ps1: collapsed the PAYG/SA conditional display name
  logic into a single generic label per platform

Include the selected target license type in the policy definition
and assignment display names for clarity in the Azure Portal.

Format: Configure Arc-enabled SQL Server (<platform>) license type to '<label>'
Examples:
- Configure Arc-enabled SQL Server (All platforms) license type to 'Pay-as-you-go'
- Configure Arc-enabled SQL Server (Linux) license type to 'License With Software Assurance'

The azurepolicy.json description remains generic since the display
name is overridden by the script at definition creation time.

Restructure both Deploy Policy and Start Remediation usage
instructions to guide users through setting variables before
running scripts. Clearly separates required vs optional parameters
with inline comments, shows progressively detailed invocations
(minimal, with subscription, with all options), and streamlines
scenario examples with descriptive comments.

Sync changes from claestom/sql-arc-policy-license-config into the
sql-server-samples fork.

azurepolicy.json:
- Add ConsentToRecurringPAYG compliance checks in existenceCondition:
  when target is PAYG, resources must also have the consent property
  to be considered compliant (handles both new transitions and
  backward compatibility for pre-consent PAYG extensions)
- Add ConsentToRecurringPAYG to the deployment template: when target
  is PAYG, the remediation sets Consented=true with a UTC timestamp;
  non-PAYG targets use the base LicenseType-only settings
- Add consentTimestamp template parameter (auto-generated via utcNow)

deployment.ps1:
- Add retry loop (5 attempts, 10s delay) for managed identity role
  assignments to handle replication delays after policy assignment
  creation; also handles Conflict responses gracefully

README.md:
- Add Recurring Billing Consent (PAYG) section documenting the
  consent behavior, compliance evaluation, and immutability note

…eenshots section