Contributes towards #279402
Make test/sanity NPM-install independent for faster initialization in the pipeline.
Fixed pipeline and tests ro fully pass on Windows x64 and MacOS x64.
Updated suite/test names to report nicely in ADO.
Ensure temp dir name is expanded on Windows to avoid ~ expansion from CLI.
Removed custom log file now that XML report is supported.
Added option to turn headless browsing on/off.