Expand Pester coverage across install, tweaks, and UI workflows (#4792)

* Harden Pester CI and discard runspace return values

* Add prioritized test backlog

* Add WinUtil action logging

* Add config integrity tests

* Add XAML control wiring tests

* Add registry and service helper tests

* Add package manager tests

* Add runspace behavior tests

* Add tweak orchestration tests

* Add install workflow tests

* Add update profile tests

* Add AppX removal tests

* Log package installer output

* Add UI state helper tests

* Pin Pester test runner version

* Expand Win11 Creator tests

* Add preferences and theme tests

* Add search filter tests

* Add compile contract tests

* Use single WinUtil session log

* Remove installer output logging helper

* Handle locked WinUtil transcript log

* Avoid appending to active transcript log

* Log install uninstall package identities

.gitignore

@@ -5,6 +5,7 @@ Microsoft.PowerShell.ConsoleHost.dll
 winutil.exe.config
 winutil.ps1
 binary/
+testResults.xml
 
 # general software/os specific
 desktop.ini