Add test for synthetic java property completion to multi-file tests

idea/idea-completion/testData/basic/multifile/SyntheticPrimitiveJavaProperty/SyntheticPrimitiveJavaProperty.dependency.java

@@ -0,0 +1,4 @@
+class JavaClassWithGetterAndSetter {
+    int getNumber() { return 0; }
+    void setNumber(int number) {}
+}

idea/idea-completion/testData/basic/multifile/SyntheticPrimitiveJavaProperty/SyntheticPrimitiveJavaProperty.kt

@@ -0,0 +1,6 @@
+// FIR_COMPARISON
+fun usage(obj: JavaClassWithGetterAndSetter) {
+    obj.<caret>
+}
+
+// EXIST: {"lookupString":"number","tailText":" (from getNumber()/setNumber())", "allLookupStrings":"getNumber, number, setNumber","itemText":"number"}