[Analysis API] Shortener: enable shortening in KDoc

^KTIJ-21103

analysis/analysis-api-impl-base/tests/org/jetbrains/kotlin/analysis/api/impl/base/test/cases/references/ShorteningResultsRenderer.kt

@@ -24,5 +24,10 @@ internal object ShorteningResultsRenderer {
                 appendLine("[qualifier] $it")
             }
         }
+        shortening.kDocQualifiersToShorten.forEach { kdoc ->
+            kdoc.element?.text?.let {
+                appendLine("[kdoc] $it")
+            }
+        }
     }
 }