Fix ClassCastException when generating unique parameter names for Records

[SougandhS]

Fixes :

java.lang.ClassCastException: class org.eclipse.jdt.core.dom.RecordDeclaration cannot be cast to class org.eclipse.jdt.core.dom.TypeDeclaration (org.eclipse.jdt.core.dom.RecordDeclaration and org.eclipse.jdt.core.dom.TypeDeclaration are in unnamed module of loader org.eclipse.osgi.internal.loader.EquinoxClassLoader @3da3cc2f)
	at org.eclipse.jdt.internal.corext.refactoring.code.makestatic.ChangeCalculator.generateUniqueParameterName(ChangeCalculator.java:227)
	at org.eclipse.jdt.internal.corext.refactoring.code.makestatic.ChangeCalculator.<init>(ChangeCalculator.java:130)
	at org.eclipse.jdt.internal.corext.refactoring.code.MakeStaticRefactoring.checkFinalConditions(MakeStaticRefactoring.java:177)
	at org.eclipse.ltk.core.refactoring.CheckConditionsOperation.run(CheckConditionsOperation.java:87)
	at org.eclipse.ltk.core.refactoring.CreateChangeOperation.run(CreateChangeOperation.java:116)
	at org.eclipse.jdt.ls.core.internal.corrections.RefactorProcessor$6.getChange(RefactorProcessor.java:1299)
	at org.eclipse.jdt.ls.core.internal.handlers.CodeActionHandler.getCodeActionFromProposal(CodeActionHandler.java:368)
	at org.eclipse.jdt.ls.core.internal.handlers.CodeActionHandler.getCodeActionCommands(CodeActionHandler.java:246)
	at org.eclipse.jdt.ls.core.internal.correction.AbstractQuickFixTest.evaluateCodeActions(AbstractQuickFixTest.java:316)
	at org.eclipse.jdt.ls.core.internal.correction.AbstractQuickFixTest.evaluateCodeActions(AbstractQuickFixTest.java:293)
	at org.eclipse.jdt.ls.core.internal.correction.AbstractQuickFixTest.assertCodeActions(AbstractQuickFixTest.java:130)
	at org.eclipse.jdt.ls.core.internal.correction.JavadocQuickFixTest.testAddJavadocForOverriddenMethodInRecord(JavadocQuickFixTest.java:1206)
	at java.base/java.lang.reflect.Method.invoke(Method.java:580)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1596)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1596)

What it does

How to test

Author checklist

• I have thoroughly tested my changes
• The change is following the coding conventions
• I have signed the Eclipse Contributor Agreement (ECA)

[SougandhS]

See eclipse-jdtls/eclipse.jdt.ls#3820 (comment)

[jjohnstn]

Looks good. Thanks.