recommendedArtifactDisplayBase

Sorry for the late small proposal, but I've been thinking about a  generic SARIF viewer and how to display paths to a human.  In a viewer  it is nice to normalize the display for paths to be relative to a single  location, or to be absolute for location not contained within the single  location.  Without the viewer and the producer agreeing out of band on a uri, or a  baseUriId name to use, the viewer does not know how to base the results  for result display.  I propose adding a property name something like  recommendedArtifactDisplayBase to the run object with a value of type  artifactLocation.  Producers MAY set this to an appropriate value if  possible.  If set, consumers that display relative paths, SHOULD display  paths to relative to the recommendedArtifactDisplayBase if the path is  contained in the recommendedArtifactDisplayBase.  If it is not contained  in recommendedArtifactDisplayBase, viewer may display it as an absolute  path (or by some other appropriate mechanism).  Jim