Break out of loop when candidate is found

@ToddGrun pointed out that the `ComponentTemplateDiagnosticPass` should stop searching a node's ancestors once it is noted as a candidate.

Author: DustinCampbell

src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/Components/ComponentTemplateDiagnosticPass.cs

@@ -54,6 +54,9 @@ TagHelperPropertyIntermediateNode or // Inside malformed ref attribute
                                 TagHelperDirectiveAttributeIntermediateNode) // Inside a directive attribute
                 {
                     _candidates.Add(new IntermediateNodeReference(Parent, node));
+
+                    // We found a candidate and can stop looking. There's no need to report multiple diagnostics for the same node.
+                    break;
                 }
             }
         }