Add structured location information to BuildCheck results

[JanKrivanek]

Context

BuildCheckResultError, BuildCheckResultWarning, BuildCheckResultInfo currently do not have structured information about location (see #10227 (comment)).
In order to do this - we'll need move IMsBuildElementLocation into Microsoft.Build.Framework and add it to IBuildCheckResult (instead of just the LocationString)

Justification

This will unlock the integration that uses the location info from the EventArgs (Binlog Viewer, Visual Studio Error Window, ...)