KT-6820 Find usages doesn't find delegated properties when searching get/set/propertyDelegated functions

#KT-6820 fixed

idea/testData/findUsages/kotlin/conventions/getAsPropertyDelegate.0.kt

@@ -0,0 +1,8 @@
+// PSI_ELEMENT: org.jetbrains.kotlin.psi.JetNamedFunction
+// OPTIONS: usages
+
+class Delegate() {
+    fun <caret>get(thisRef: Any?, propertyMetadata: PropertyMetadata): String = ":)"
+}
+
+val p: String by Delegate()

idea/testData/findUsages/kotlin/conventions/getAsPropertyDelegate.results.txt

@@ -0,0 +1 @@
+Property delegation (8: 15) val p: String by Delegate()

idea/testData/findUsages/kotlin/conventions/propertyDelegatedFunction.0.kt

@@ -0,0 +1,13 @@
+// PSI_ELEMENT: org.jetbrains.kotlin.psi.JetNamedFunction
+// OPTIONS: usages
+
+class Delegate() {
+    fun get(thisRef: Any?, propertyMetadata: PropertyMetadata): String = ":)"
+    fun set(thisRef: Any?, propertyMetadata: PropertyMetadata, value: String) {
+    }
+
+    fun <caret>propertyDelegated(propertyMetadata: PropertyMetadata) {
+    }
+}
+
+var p: String by Delegate()

idea/testData/findUsages/kotlin/conventions/propertyDelegatedFunction.results.txt

@@ -0,0 +1 @@
+Property delegation (13: 15) var p: String by Delegate()

idea/testData/findUsages/kotlin/conventions/setAsPropertyDelegate.0.kt

@@ -0,0 +1,11 @@
+// PSI_ELEMENT: org.jetbrains.kotlin.psi.JetNamedFunction
+// OPTIONS: usages
+
+class Delegate() {
+    fun get(thisRef: Any?, propertyMetadata: PropertyMetadata): String = ":)"
+    fun <caret>set(thisRef: Any?, propertyMetadata: PropertyMetadata, value: String) {
+
+    }
+}
+
+var p: String by Delegate()

idea/testData/findUsages/kotlin/conventions/setAsPropertyDelegate.results.txt

@@ -0,0 +1 @@
+Property delegation (11: 15) var p: String by Delegate()