Completion fails with exception "Toplevel class has no fqName" (KT-5119)

Groovy scripts files can create PsiClasses with null qualfied names (getQualifiedName()) and names (getName()).

 #KT-5119 Fixed

idea/testData/completion/basic/multifile/GroovyClassNameCompletionFromDefaultPackage/GroovyClassNameCompletionFromDefaultPackage.kt

@@ -0,0 +1,7 @@
+class TestKotlin
+
+val test = Test<caret>
+
+// EXIST: TestKotlin
+// EXIST: TestGroovyNormal
+// EXIST: TestGroovyScript

idea/testData/completion/basic/multifile/GroovyClassNameCompletionFromDefaultPackage/normalname.groovy

@@ -0,0 +1,2 @@
+public class TestGroovyNormal {
+}

idea/testData/completion/basic/multifile/GroovyClassNameCompletionFromDefaultPackage/script-file-no-classes.groovy

@@ -0,0 +1,3 @@
+def method() {
+
+}

idea/testData/completion/basic/multifile/GroovyClassNameCompletionFromDefaultPackage/script-file-with-class.groovy

@@ -0,0 +1,2 @@
+public class TestGroovyScript {
+}

idea/testData/completion/basic/multifile/GroovyClassNameCompletionFromNonDefaultPackage/GroovyClassNameCompletionFromNonDefaultPackage.kt

@@ -0,0 +1,10 @@
+package foo
+
+class TestKotlin
+
+val test = Test<caret>
+
+// EXIST: TestKotlin
+// EXIST: TestGroovyNormal
+// EXIST: TestGroovyScript
+// INVOCATION_COUNT: 2

idea/testData/completion/basic/multifile/GroovyClassNameCompletionFromNonDefaultPackage/normalname.groovy

@@ -0,0 +1,2 @@
+public class TestGroovyNormal {
+}

idea/testData/completion/basic/multifile/GroovyClassNameCompletionFromNonDefaultPackage/script-file-no-classes.groovy

@@ -0,0 +1,3 @@
+def method() {
+
+}

idea/testData/completion/basic/multifile/GroovyClassNameCompletionFromNonDefaultPackage/script-file-with-class.groovy

@@ -0,0 +1,2 @@
+public class TestGroovyScript {
+}