Fix highlight region end column calculation (#1210)

extensions/ql-vscode/src/remote-queries/sarif-processing.ts

@@ -169,7 +169,10 @@ function getHighlightedRegion(region: sarif.Region): HighlightedRegion {
     startLine,
     startColumn,
     endLine,
-    endColumn
+
+    // parseSarifRegion currently shifts the end column by 1 to account 
+    // for the way vscode counts columns so we need to shift it back.
+    endColumn: endColumn + 1
   };
 }
 

extensions/ql-vscode/test/pure-tests/sarif-processing.test.ts

@@ -579,7 +579,7 @@ describe('SARIF processing', () => {
           startLine: 35,
           startColumn: 20,
           endLine: 35,
-          endColumn: 59
+          endColumn: 60
         }
       });
       expect(message.tokens[2].t).to.equal('text');