Optimizing VS component installer to speed up CI builds

[jonthysell]

With the new VMs, shaving down the current ~15min install step.

• Updated the Install-VSFeatures.ps1 script:
  • If VS is already installed, defaults to using the local VS installer, rather than downloading the web installer
  • More output so you can track what's going on
  • When using the web installer, optionally cleanup downloaded files afterward
  • More cli parameters for more control of what goes where
  • Setting us up for Create a one-line command to install VS environment #4523
• Updating the yamls to evaluate and pass parameters properly
• Removing the need to run the installer at all, where necessary
• Fixed the CLI so it correctly acknowledges the build agents have the right VS components, so it therefore finds MSBuild
  • Added more verbose logging to the MSBuild search
• Added a task (disabled, but controlled via parameter) to list out all the VS components on the build agent, so we can debug missing dependencies faster

Closes #4450

Microsoft Reviewers: Open in CodeFlow

[JunielKatarn]

Changes seem fine, but out of curiosity:
How does adding verbosity increase the script's performance?

[jonthysell]

Changes seem fine, but out of curiosity:
How does adding verbosity increase the script's performance?

Sorry, this is an investigation / work-in progress. I'm first going to add more logging to the script so I can see where the time is being spent, and get a list of what is/isn't installed on the machines as part of the logging, then fine tune things.

[NickGerleman]

nit spelling