handle installation scope for PowerShell modules

[Gabriel Dufresne (GabrielDuf)]

This pull request refines how custom installation scopes are handled for PowerShell and PowerShell 7 package managers, ensuring that scope selection is correctly applied only when supported and that user-selected scopes override auto-detected ones. It also adds comprehensive regression tests to prevent future issues related to scope handling.

Improvements to scope handling logic:

• Updated ManagerCapabilities to introduce SupportsCustomScopesOnUpdate and SupportsCustomScopesOnUninstall, allowing more granular control over when custom scopes are available for different operations (Install, Update, Uninstall).
• Modified PowerShell and PowerShell 7 manager capability definitions to correctly set these new flags, reflecting that only install operations support custom scopes for PowerShell, and only install/uninstall as appropriate for PowerShell 7.
• Refined logic in ApplyProfileEnableState to enable or disable scope selection based on these new capability flags and the current operation type.

Command parameter generation fixes:

• Changed parameter generation in both PowerShell and PowerShell 7 helpers so that an explicitly chosen scope in the options dialog always overrides the detected scope, and scope parameters are only emitted when supported by the operation type.
  Regression and behavior tests:

• Added targeted tests to ensure scope selection logic works as intended, including cases where explicit scopes override detected scopes, and that scope parameters are omitted when not supported. Also verifies the new capability flags.
  These changes ensure more predictable and correct behavior for package installation, update, and uninstall operations across supported PowerShell environments.