ci: use RAM disk for Windows tests
ci: use RAM disk for Windows tests

Windows is IO bound which causes tests to take significantly longer than Linux.

With this change we introduce the use of RAM disk on Windows instead of a physical disk to store tests projects files which reduces this overhead.

While Circle CI docs mention to use `ImDisk` https://support.circleci.com/hc/en-us/articles/4411520952091-Create-a-windows-RAM-disk, we use a different tool Arsenal Image Mounter `aim_ll` due to following Node.js issue: https://github.com/nodejs/node/issues/6861

The `aim_ll` CLI is based on `ImDisk` and is parameter compatible.

From testing a full run of the Windows E2E full test suit goes from ~56min to ~35mins

With RAM disk
https://app.circleci.com/pipelines/github/angular/angular-cli/23286/workflows/4b1dc425-f7ed-49d6-aeba-b2c503d08756/jobs/309423/parallel-runs/2?filterBy=ALL

Without RAM Disk
https://app.circleci.com/pipelines/github/angular/angular-cli/23256/workflows/3f551c3c-fbb0-445f-80f9-1801d4adc664/jobs/309312

angular/angular-cli,angular/angular-cli,clydin/angular-cli,clydin/angular-cli,clydin/angular-cli,clydin/angular-cli,angular/angular-cli,angular/angular-cli