Change kvm install to install desktop x86 version along with the requested version

[PradeepKadubandi]

Currently VS runs only desktop x86 version of KLR for KPM and Design time host apps ...

After VS support for multiple KRE's , if the user upgraded only coreclr or x64 desktop version without upgrading the desktop version first, VS will try to find a matching desktop x86 version for the version in default.txt and bails with an error saying it can not find KRE.(See the tooling bug: http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/947518 ).

It would be good to fix kvm to install desktop x86 version if user requested other type and desktop x86 version is not present so that VS will not run into the above issue.

[glennc]

We can add a -all flag to download all combinations of packages for install or upgrade.