Migrate LanguageVersionTests to JUnit5

Also move LanguageVersionTests into their language packages
and add missing tests

pmd-swift/src/test/java/net/sourceforge/pmd/lang/swift/LanguageVersionTest.java

@@ -0,0 +1,18 @@
+/*
+ * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
+ */
+
+package net.sourceforge.pmd.lang.swift;
+
+import java.util.Arrays;
+import java.util.Collection;
+
+import net.sourceforge.pmd.AbstractLanguageVersionTest;
+
+class LanguageVersionTest extends AbstractLanguageVersionTest {
+
+    static Collection<TestDescriptor> data() {
+        return Arrays.asList(new TestDescriptor(SwiftLanguageModule.NAME, SwiftLanguageModule.TERSE_NAME, "",
+                getLanguage(SwiftLanguageModule.NAME).getDefaultVersion()));
+    }
+}